Convert option descriptions to Markdown

src/libexpr/common-eval-args.cc

@@ -14,14 +14,14 @@ MixEvalArgs::MixEvalArgs()
 {
     addFlag({
         .longName = "arg",
-        .description = "argument to be passed to Nix functions",
+        .description = "Pass the value *expr* as the argument *name* to Nix functions.",
         .labels = {"name", "expr"},
         .handler = {[&](std::string name, std::string expr) { autoArgs[name] = 'E' + expr; }}
     });
 
     addFlag({
         .longName = "argstr",
-        .description = "string-valued argument to be passed to Nix functions",
+        .description = "Pass the string *string* as the argument *name* to Nix functions.",
         .labels = {"name", "string"},
         .handler = {[&](std::string name, std::string s) { autoArgs[name] = 'S' + s; }},
     });
@@ -29,14 +29,14 @@ MixEvalArgs::MixEvalArgs()
     addFlag({
         .longName = "include",
         .shortName = 'I',
-        .description = "add a path to the list of locations used to look up `<...>` file names",
+        .description = "Add *path* to the list of locations used to look up `<...>` file names.",
         .labels = {"path"},
         .handler = {[&](std::string s) { searchPath.push_back(s); }}
     });
 
     addFlag({
         .longName = "impure",
-        .description = "allow access to mutable paths and repositories",
+        .description = "Allow access to mutable paths and repositories.",
         .handler = {[&]() {
             evalSettings.pureEval = false;
         }},
@@ -44,7 +44,7 @@ MixEvalArgs::MixEvalArgs()
 
     addFlag({
         .longName = "override-flake",
-        .description = "override a flake registry value",
+        .description = "Override the flake registries, redirecting *original-ref* to *resolved-ref*.",
         .labels = {"original-ref", "resolved-ref"},
         .handler = {[&](std::string _from, std::string _to) {
             auto from = parseFlakeRef(_from, absPath("."));

src/libmain/common-args.cc

@@ -10,25 +10,25 @@ MixCommonArgs::MixCommonArgs(const string & programName)
     addFlag({
         .longName = "verbose",
         .shortName = 'v',
-        .description = "increase verbosity level",
+        .description = "Increase the logging verbosity level.",
         .handler = {[]() { verbosity = (Verbosity) (verbosity + 1); }},
     });
 
     addFlag({
         .longName = "quiet",
-        .description = "decrease verbosity level",
+        .description = "Decrease the logging verbosity level.",
         .handler = {[]() { verbosity = verbosity > lvlError ? (Verbosity) (verbosity - 1) : lvlError; }},
     });
 
     addFlag({
         .longName = "debug",
-        .description = "enable debug output",
+        .description = "Set the logging verbosity level to 'debug'.",
         .handler = {[]() { verbosity = lvlDebug; }},
     });
 
     addFlag({
         .longName = "option",
-        .description = "set a Nix configuration option (overriding `nix.conf`)",
+        .description = "Set the Nix configuration setting *name* to *value* (overriding `nix.conf`).",
         .labels = {"name", "value"},
         .handler = {[](std::string name, std::string value) {
             try {
@@ -51,8 +51,7 @@ MixCommonArgs::MixCommonArgs(const string & programName)
 
     addFlag({
         .longName = "log-format",
-        .description = "format of log output; `raw`, `internal-json`, `bar` "
+        .description = "Set the format of log output; one of `raw`, `internal-json`, `bar` or `bar-with-logs`.",
-                        "or `bar-with-logs`",
         .labels = {"format"},
         .handler = {[](std::string format) { setLogFormat(format); }},
     });
@@ -60,7 +59,7 @@ MixCommonArgs::MixCommonArgs(const string & programName)
     addFlag({
         .longName = "max-jobs",
         .shortName = 'j',
-        .description = "maximum number of parallel builds",
+        .description = "The maximum number of parallel builds.",
         .labels = Strings{"jobs"},
         .handler = {[=](std::string s) {
             settings.set("max-jobs", s);

src/libmain/common-args.hh

@@ -16,7 +16,7 @@ struct MixDryRun : virtual Args
 
     MixDryRun()
     {
-        mkFlag(0, "dry-run", "show what this command would do without doing it", &dryRun);
+        mkFlag(0, "dry-run", "Show what this command would do without doing it.", &dryRun);
     }
 };
 
@@ -26,7 +26,7 @@ struct MixJSON : virtual Args
 
     MixJSON()
     {
-        mkFlag(0, "json", "produce JSON output", &json);
+        mkFlag(0, "json", "Produce output in JSON format, suitable for consumption by another program.", &json);
     }
 };
 

src/libmain/shared.cc

@@ -186,27 +186,27 @@ LegacyArgs::LegacyArgs(const std::string & programName,
     addFlag({
         .longName = "no-build-output",
         .shortName = 'Q',
-        .description = "do not show build output",
+        .description = "Do not show build output.",
         .handler = {[&]() {setLogFormat(LogFormat::raw); }},
     });
 
     addFlag({
         .longName = "keep-failed",
         .shortName ='K',
-        .description = "keep temporary directories of failed builds",
+        .description = "Keep temporary directories of failed builds.",
         .handler = {&(bool&) settings.keepFailed, true},
     });
 
     addFlag({
         .longName = "keep-going",
         .shortName ='k',
-        .description = "keep going after a build fails",
+        .description = "Keep going after a build fails.",
         .handler = {&(bool&) settings.keepGoing, true},
     });
 
     addFlag({
         .longName = "fallback",
-        .description = "build from source if substitution fails",
+        .description = "Build from source if substitution fails.",
         .handler = {&(bool&) settings.tryFallback, true},
     });
 
@@ -225,19 +225,19 @@ LegacyArgs::LegacyArgs(const std::string & programName,
         });
     };
 
-    intSettingAlias(0, "cores", "maximum number of CPU cores to use inside a build", "cores");
+    intSettingAlias(0, "cores", "Maximum number of CPU cores to use inside a build.", "cores");
-    intSettingAlias(0, "max-silent-time", "number of seconds of silence before a build is killed", "max-silent-time");
+    intSettingAlias(0, "max-silent-time", "Number of seconds of silence before a build is killed.", "max-silent-time");
-    intSettingAlias(0, "timeout", "number of seconds before a build is killed", "timeout");
+    intSettingAlias(0, "timeout", "Number of seconds before a build is killed.", "timeout");
 
-    mkFlag(0, "readonly-mode", "do not write to the Nix store",
+    mkFlag(0, "readonly-mode", "Do not write to the Nix store.",
         &settings.readOnlyMode);
 
-    mkFlag(0, "no-gc-warning", "disable warning about not using '--add-root'",
+    mkFlag(0, "no-gc-warning", "Disable warnings about not using `--add-root`.",
         &gcWarning, false);
 
     addFlag({
         .longName = "store",
-        .description = "URI of the Nix store to use",
+        .description = "The URL of the Nix store to use.",
         .labels = {"store-uri"},
         .handler = {&(std::string&) settings.storeUri},
     });

src/nix/add-to-store.cc

@@ -19,7 +19,7 @@ struct CmdAddToStore : MixDryRun, StoreCommand
         addFlag({
             .longName = "name",
             .shortName = 'n',
-            .description = "name component of the store path",
+            .description = "Override the name component of the store path. It defaults to the base name of *path*.",
             .labels = {"name"},
             .handler = {&namePart},
         });

src/nix/build.cc

@@ -19,7 +19,7 @@ struct CmdBuild : InstallablesCommand, MixDryRun, MixJSON, MixProfile
         addFlag({
             .longName = "out-link",
             .shortName = 'o',
-            .description = "path of the symlink to the build result",
+            .description = "Use *path* as prefix for the symlinks to the build results. It defaults to `result`.",
             .labels = {"path"},
             .handler = {&outLink},
             .completer = completePath
@@ -27,13 +27,13 @@ struct CmdBuild : InstallablesCommand, MixDryRun, MixJSON, MixProfile
 
         addFlag({
             .longName = "no-link",
-            .description = "do not create a symlink to the build result",
+            .description = "Do not create symlinks to the build results.",
             .handler = {&outLink, Path("")},
         });
 
         addFlag({
             .longName = "rebuild",
-            .description = "rebuild an already built package and compare the result to the existing store paths",
+            .description = "Rebuild an already built package and compare the result to the existing store paths.",
             .handler = {&buildMode, bmCheck},
         });
     }

src/nix/bundle.cc

@@ -16,7 +16,7 @@ struct CmdBundle : InstallableCommand
     {
         addFlag({
             .longName = "bundler",
-            .description = "use custom bundler",
+            .description = fmt("Use a custom bundler instead of the default (`%s`).", bundler),
             .labels = {"flake-url"},
             .handler = {&bundler},
             .completer = {[&](size_t, std::string_view prefix) {
@@ -27,7 +27,7 @@ struct CmdBundle : InstallableCommand
         addFlag({
             .longName = "out-link",
             .shortName = 'o',
-            .description = "path of the symlink to the build result",
+            .description = "Override the name of the symlink to the build result. It defaults to the base name of the app.",
             .labels = {"path"},
             .handler = {&outLink},
             .completer = completePath

src/nix/command.cc

@@ -65,18 +65,18 @@ StorePathsCommand::StorePathsCommand(bool recursive)
     if (recursive)
         addFlag({
             .longName = "no-recursive",
-            .description = "apply operation to specified paths only",
+            .description = "Apply operation to specified paths only.",
             .handler = {&this->recursive, false},
         });
     else
         addFlag({
             .longName = "recursive",
             .shortName = 'r',
-            .description = "apply operation to closure of the specified paths",
+            .description = "Apply operation to closure of the specified paths.",
             .handler = {&this->recursive, true},
         });
 
-    mkFlag(0, "all", "apply operation to the entire store", &all);
+    mkFlag(0, "all", "Apply the operation to every store path.", &all);
 }
 
 void StorePathsCommand::run(ref<Store> store)
@@ -133,7 +133,7 @@ MixProfile::MixProfile()
 {
     addFlag({
         .longName = "profile",
-        .description = "profile to update",
+        .description = "The profile to update.",
         .labels = {"path"},
         .handler = {&profile},
         .completer = completePath
@@ -190,14 +190,14 @@ MixEnvironment::MixEnvironment() : ignoreEnvironment(false)
     addFlag({
         .longName = "ignore-environment",
         .shortName = 'i',
-        .description = "clear the entire environment (except those specified with --keep)",
+        .description = "Clear the entire environment (except those specified with `--keep`).",
         .handler = {&ignoreEnvironment, true},
     });
 
     addFlag({
         .longName = "keep",
         .shortName = 'k',
-        .description = "keep specified environment variable",
+        .description = "Keep the environment variable *name*.",
         .labels = {"name"},
         .handler = {[&](std::string s) { keep.insert(s); }},
     });
@@ -205,7 +205,7 @@ MixEnvironment::MixEnvironment() : ignoreEnvironment(false)
     addFlag({
         .longName = "unset",
         .shortName = 'u',
-        .description = "unset specified environment variable",
+        .description = "Unset the environment variable *name*.",
         .labels = {"name"},
         .handler = {[&](std::string s) { unset.insert(s); }},
     });

src/nix/copy.cc

@@ -21,28 +21,28 @@ struct CmdCopy : StorePathsCommand
     {
         addFlag({
             .longName = "from",
-            .description = "URI of the source Nix store",
+            .description = "URL of the source Nix store.",
             .labels = {"store-uri"},
             .handler = {&srcUri},
         });
 
         addFlag({
             .longName = "to",
-            .description = "URI of the destination Nix store",
+            .description = "URL of the destination Nix store.",
             .labels = {"store-uri"},
             .handler = {&dstUri},
         });
 
         addFlag({
             .longName = "no-check-sigs",
-            .description = "do not require that paths are signed by trusted keys",
+            .description = "Do not require that paths are signed by trusted keys.",
             .handler = {&checkSigs, NoCheckSigs},
         });
 
         addFlag({
             .longName = "substitute-on-destination",
             .shortName = 's',
-            .description = "whether to try substitutes on the destination store (only supported by SSH)",
+            .description = "Whether to try substitutes on the destination store (only supported by SSH stores).",
             .handler = {&substitute, Substitute},
         });
 

src/nix/develop.cc

@@ -204,7 +204,7 @@ struct Common : InstallableCommand, MixProfile
     {
         addFlag({
             .longName = "redirect",
-            .description = "redirect a store path to a mutable location",
+            .description = "Redirect a store path to a mutable location.",
             .labels = {"installable", "outputs-dir"},
             .handler = {[&](std::string installable, std::string outputsDir) {
                 redirects.push_back({installable, outputsDir});
@@ -334,7 +334,7 @@ struct CmdDevelop : Common, MixEnvironment
         addFlag({
             .longName = "command",
             .shortName = 'c',
-            .description = "command and arguments to be executed instead of an interactive shell",
+            .description = "Instead of starting an interactive shell, start the specified command and arguments.",
             .labels = {"command", "args"},
             .handler = {[&](std::vector<std::string> ss) {
                 if (ss.empty()) throw UsageError("--command requires at least one argument");
@@ -344,38 +344,38 @@ struct CmdDevelop : Common, MixEnvironment
 
         addFlag({
             .longName = "phase",
-            .description = "phase to run (e.g. `build` or `configure`)",
+            .description = "The stdenv phase to run (e.g. `build` or `configure`).",
             .labels = {"phase-name"},
             .handler = {&phase},
         });
 
         addFlag({
             .longName = "configure",
-            .description = "run the configure phase",
+            .description = "Run the `configure` phase.",
             .handler = {&phase, {"configure"}},
         });
 
         addFlag({
             .longName = "build",
-            .description = "run the build phase",
+            .description = "Run the `build` phase.",
             .handler = {&phase, {"build"}},
         });
 
         addFlag({
             .longName = "check",
-            .description = "run the check phase",
+            .description = "Run the `check` phase.",
             .handler = {&phase, {"check"}},
         });
 
         addFlag({
             .longName = "install",
-            .description = "run the install phase",
+            .description = "Run the `install` phase.",
             .handler = {&phase, {"install"}},
         });
 
         addFlag({
             .longName = "installcheck",
-            .description = "run the installcheck phase",
+            .description = "Run the `installcheck` phase.",
             .handler = {&phase, {"installCheck"}},
         });
     }

src/nix/eval.cc

@@ -18,18 +18,18 @@ struct CmdEval : MixJSON, InstallableCommand
 
     CmdEval()
     {
-        mkFlag(0, "raw", "print strings unquoted", &raw);
+        mkFlag(0, "raw", "Print strings without quotes or escaping.", &raw);
 
         addFlag({
             .longName = "apply",
-            .description = "apply a function to each argument",
+            .description = "Apply the function *expr* to each argument.",
             .labels = {"expr"},
             .handler = {&apply},
         });
 
         addFlag({
             .longName = "write-to",
-            .description = "write a string or attrset of strings to 'path'",
+            .description = "Write a string or attrset of strings to *path*.",
             .labels = {"path"},
             .handler = {&writeTo},
         });

src/nix/flake.cc

@@ -222,7 +222,7 @@ struct CmdFlakeCheck : FlakeCommand
     {
         addFlag({
             .longName = "no-build",
-            .description = "do not build checks",
+            .description = "Do not build checks.",
             .handler = {&build, false}
         });
     }
@@ -573,7 +573,7 @@ struct CmdFlakeInitCommon : virtual Args, EvalCommand
         addFlag({
             .longName = "template",
             .shortName = 't',
-            .description = "the template to use",
+            .description = "The template to use.",
             .labels = {"template"},
             .handler = {&templateUrl},
             .completer = {[&](size_t, std::string_view prefix) {
@@ -717,7 +717,7 @@ struct CmdFlakeClone : FlakeCommand
         addFlag({
             .longName = "dest",
             .shortName = 'f',
-            .description = "destination path",
+            .description = "Clone the flake to path *dest*.",
             .labels = {"path"},
             .handler = {&destDir}
         });
@@ -807,7 +807,7 @@ struct CmdFlakeShow : FlakeCommand
     {
         addFlag({
             .longName = "legacy",
-            .description = "show the contents of the 'legacyPackages' output",
+            .description = "Show the contents of the `legacyPackages` output.",
             .handler = {&showLegacy, true}
         });
     }

src/nix/hash.cc

@@ -19,15 +19,15 @@ struct CmdHashBase : Command
 
     CmdHashBase(FileIngestionMethod mode) : mode(mode)
     {
-        mkFlag(0, "sri", "print hash in SRI format", &base, SRI);
+        mkFlag(0, "sri", "Print the hash in SRI format.", &base, SRI);
-        mkFlag(0, "base64", "print hash in base-64", &base, Base64);
+        mkFlag(0, "base64", "Print the hash in base-64 format.", &base, Base64);
-        mkFlag(0, "base32", "print hash in base-32 (Nix-specific)", &base, Base32);
+        mkFlag(0, "base32", "Print the hash in base-32 (Nix-specific) format.", &base, Base32);
-        mkFlag(0, "base16", "print hash in base-16", &base, Base16);
+        mkFlag(0, "base16", "Print the hash in base-16 format.", &base, Base16);
         addFlag(Flag::mkHashTypeFlag("type", &ht));
         #if 0
         mkFlag()
             .longName("modulo")
-            .description("compute hash modulo specified string")
+            .description("Compute the hash modulo specified the string.")
             .labels({"modulus"})
             .dest(&modulus);
         #endif
@@ -40,15 +40,14 @@ struct CmdHashBase : Command
 
     std::string description() override
     {
-        const char* d;
         switch (mode) {
         case FileIngestionMethod::Flat:
-            d = "print cryptographic hash of a regular file";
+            return  "print cryptographic hash of a regular file";
-            break;
         case FileIngestionMethod::Recursive:
-            d = "print cryptographic hash of the NAR serialisation of a path";
+            return "print cryptographic hash of the NAR serialisation of a path";
+        default:
+            assert(false);
         };
-        return d;
     }
 
     void run() override

src/nix/installables.cc

@@ -60,37 +60,37 @@ MixFlakeOptions::MixFlakeOptions()
 {
     addFlag({
         .longName = "recreate-lock-file",
-        .description = "recreate lock file from scratch",
+        .description = "Recreate the flake's lock file from scratch.",
         .handler = {&lockFlags.recreateLockFile, true}
     });
 
     addFlag({
         .longName = "no-update-lock-file",
-        .description = "do not allow any updates to the lock file",
+        .description = "Do not allow any updates to the flake's lock file.",
         .handler = {&lockFlags.updateLockFile, false}
     });
 
     addFlag({
         .longName = "no-write-lock-file",
-        .description = "do not write the newly generated lock file",
+        .description = "Do not write the flake's newly generated lock file.",
         .handler = {&lockFlags.writeLockFile, false}
     });
 
     addFlag({
         .longName = "no-registries",
-        .description = "don't use flake registries",
+        .description = "Don't allow lookups in the flake registries.",
         .handler = {&lockFlags.useRegistries, false}
     });
 
     addFlag({
         .longName = "commit-lock-file",
-        .description = "commit changes to the lock file",
+        .description = "Commit changes to the flake's lock file.",
         .handler = {&lockFlags.commitLockFile, true}
     });
 
     addFlag({
         .longName = "update-input",
-        .description = "update a specific flake input",
+        .description = "Update a specific flake input (ignoring its previous entry in the lock file).",
         .labels = {"input-path"},
         .handler = {[&](std::string s) {
             lockFlags.inputUpdates.insert(flake::parseInputPath(s));
@@ -103,7 +103,7 @@ MixFlakeOptions::MixFlakeOptions()
 
     addFlag({
         .longName = "override-input",
-        .description = "override a specific flake input (e.g. `dwarffs/nixpkgs`)",
+        .description = "Override a specific flake input (e.g. `dwarffs/nixpkgs`).",
         .labels = {"input-path", "flake-url"},
         .handler = {[&](std::string inputPath, std::string flakeRef) {
             lockFlags.inputOverrides.insert_or_assign(
@@ -114,7 +114,7 @@ MixFlakeOptions::MixFlakeOptions()
 
     addFlag({
         .longName = "inputs-from",
-        .description = "use the inputs of the specified flake as registry entries",
+        .description = "Use the inputs of the specified flake as registry entries.",
         .labels = {"flake-url"},
         .handler = {[&](std::string flakeRef) {
             auto evalState = getEvalState();
@@ -143,7 +143,7 @@ SourceExprCommand::SourceExprCommand()
     addFlag({
         .longName = "file",
         .shortName = 'f',
-        .description = "evaluate *file* rather than the default",
+        .description = "Interpret installables as attribute paths relative to the Nix expression stored in *file*.",
         .labels = {"file"},
         .handler = {&file},
         .completer = completePath
@@ -151,14 +151,14 @@ SourceExprCommand::SourceExprCommand()
 
     addFlag({
         .longName = "expr",
-        .description = "evaluate attributes from *expr*",
+        .description = "Interpret installables as attribute paths relative to the Nix expression *expr*.",
         .labels = {"expr"},
         .handler = {&expr}
     });
 
     addFlag({
         .longName = "derivation",
-        .description = "operate on the store derivation rather than its outputs",
+        .description = "Operate on the store derivation rather than its outputs.",
         .handler = {&operateOn, OperateOn::Derivation},
     });
 }

src/nix/ls.cc

@@ -17,9 +17,9 @@ struct MixLs : virtual Args, MixJSON
 
     MixLs()
     {
-        mkFlag('R', "recursive", "list subdirectories recursively", &recursive);
+        mkFlag('R', "recursive", "List subdirectories recursively.", &recursive);
-        mkFlag('l', "long", "show more file information", &verbose);
+        mkFlag('l', "long", "Show detailed file information.", &verbose);
-        mkFlag('d', "directory", "show directories rather than their contents", &showDirectory);
+        mkFlag('d', "directory", "Show directories rather than their contents.", &showDirectory);
     }
 
     void listText(ref<FSAccessor> accessor)

src/nix/main.cc

@@ -69,15 +69,15 @@ struct NixArgs : virtual MultiCommand, virtual MixCommonArgs
 
         addFlag({
             .longName = "help",
-            .description = "show usage information",
+            .description = "Show usage information.",
             .handler = {[&]() { if (!completions) showHelpAndExit(); }},
         });
 
         addFlag({
             .longName = "help-config",
-            .description = "show configuration options",
+            .description = "Show configuration settings.",
             .handler = {[&]() {
-                std::cout << "The following configuration options are available:\n\n";
+                std::cout << "The following configuration settings are available:\n\n";
                 Table2 tbl;
                 std::map<std::string, Config::SettingInfo> settings;
                 globalConfig.getSettings(settings);
@@ -91,25 +91,25 @@ struct NixArgs : virtual MultiCommand, virtual MixCommonArgs
         addFlag({
             .longName = "print-build-logs",
             .shortName = 'L',
-            .description = "print full build logs on stderr",
+            .description = "Print full build logs on standard error.",
             .handler = {[&]() {setLogFormat(LogFormat::barWithLogs); }},
         });
 
         addFlag({
             .longName = "version",
-            .description = "show version information",
+            .description = "Show version information.",
             .handler = {[&]() { if (!completions) printVersion(programName); }},
         });
 
         addFlag({
             .longName = "no-net",
-            .description = "disable substituters and consider all previously downloaded files up-to-date",
+            .description = "Disable substituters and consider all previously downloaded files up-to-date.",
             .handler = {[&]() { useNet = false; }},
         });
 
         addFlag({
             .longName = "refresh",
-            .description = "consider all previously downloaded files out-of-date",
+            .description = "Consider all previously downloaded files out-of-date.",
             .handler = {[&]() { refresh = true; }},
         });
     }

src/nix/path-info.cc

@@ -18,10 +18,10 @@ struct CmdPathInfo : StorePathsCommand, MixJSON
 
     CmdPathInfo()
     {
-        mkFlag('s', "size", "print size of the NAR dump of each path", &showSize);
+        mkFlag('s', "size", "Print the size of the NAR serialisation of each path.", &showSize);
-        mkFlag('S', "closure-size", "print sum size of the NAR dumps of the closure of each path", &showClosureSize);
+        mkFlag('S', "closure-size", "Print the sum of the sizes of the NAR serialisations of the closure of each path.", &showClosureSize);
-        mkFlag('h', "human-readable", "with -s and -S, print sizes like 1K 234M 5.67G etc.", &humanReadable);
+        mkFlag('h', "human-readable", "With `-s` and `-S`, print sizes in a human-friendly format such as `5.67G`.", &humanReadable);
-        mkFlag(0, "sigs", "show signatures", &showSigs);
+        mkFlag(0, "sigs", "Show signatures.", &showSigs);
     }
 
     std::string description() override

src/nix/prefetch.cc

@@ -258,14 +258,14 @@ struct CmdStorePrefetchFile : StoreCommand, MixJSON
     {
         addFlag({
             .longName = "name",
-            .description = "store path name",
+            .description = "Override the name component of the resulting store path. It defaults to the base name of *url*.",
             .labels = {"name"},
             .handler = {&name}
         });
 
         addFlag({
             .longName = "expected-hash",
-            .description = "expected hash of the file",
+            .description = "The expected hash of the file.",
             .labels = {"hash"},
             .handler = {[&](std::string s) {
                 expectedHash = Hash::parseAny(s, hashType);
@@ -276,7 +276,9 @@ struct CmdStorePrefetchFile : StoreCommand, MixJSON
 
         addFlag({
             .longName = "executable",
-            .description = "make the resulting file executable",
+            .description =
+                "Make the resulting file executable. Note that this causes the "
+                "resulting hash to be a NAR hash rather than a flat file hash.",
             .handler = {&executable, true},
         });
 

src/nix/run.cc

@@ -72,7 +72,7 @@ struct CmdShell : InstallablesCommand, RunCommon, MixEnvironment
         addFlag({
             .longName = "command",
             .shortName = 'c',
-            .description = "command and arguments to be executed; defaults to '$SHELL'",
+            .description = "Command and arguments to be executed, defaulting to `$SHELL`",
             .labels = {"command", "args"},
             .handler = {[&](std::vector<std::string> ss) {
                 if (ss.empty()) throw UsageError("--command requires at least one argument");

src/nix/show-derivation.cc

@@ -19,7 +19,7 @@ struct CmdShowDerivation : InstallablesCommand
         addFlag({
             .longName = "recursive",
             .shortName = 'r',
-            .description = "include the dependencies of the specified derivations",
+            .description = "Include the dependencies of the specified derivations.",
             .handler = {&recursive, true}
         });
     }

src/nix/sigs.cc

@@ -16,7 +16,7 @@ struct CmdCopySigs : StorePathsCommand
         addFlag({
             .longName = "substituter",
             .shortName = 's',
-            .description = "use signatures from specified store",
+            .description = "Use signatures from specified store.",
             .labels = {"store-uri"},
             .handler = {[&](std::string s) { substituterUris.push_back(s); }},
         });
@@ -101,7 +101,7 @@ struct CmdSignPaths : StorePathsCommand
         addFlag({
             .longName = "key-file",
             .shortName = 'k',
-            .description = "file containing the secret signing key",
+            .description = "File containing the secret signing key.",
             .labels = {"file"},
             .handler = {&secretKeyFile},
             .completer = completePath
@@ -150,7 +150,7 @@ struct CmdKeyGenerateSecret : Command
     {
         addFlag({
             .longName = "key-name",
-            .description = "identifier of the key (e.g. `cache.example.org-1`)",
+            .description = "Identifier of the key (e.g. `cache.example.org-1`).",
             .labels = {"name"},
             .handler = {&keyName},
         });

src/nix/store-delete.cc

@@ -13,7 +13,7 @@ struct CmdStoreDelete : StorePathsCommand
     {
         addFlag({
             .longName = "ignore-liveness",
-            .description = "do not check whether the paths are reachable from a root",
+            .description = "Do not check whether the paths are reachable from a root.",
             .handler = {&options.ignoreLiveness, true}
         });
     }

src/nix/store-gc.cc

@@ -13,7 +13,7 @@ struct CmdStoreGC : StoreCommand, MixDryRun
     {
         addFlag({
             .longName = "max",
-            .description = "stop after freeing `n` bytes of disk space",
+            .description = "Stop after freeing *n* bytes of disk space.",
             .labels = {"n"},
             .handler = {&options.maxFreed}
         });

src/nix/upgrade-nix.cc

@@ -19,14 +19,14 @@ struct CmdUpgradeNix : MixDryRun, StoreCommand
         addFlag({
             .longName = "profile",
             .shortName = 'p',
-            .description = "the Nix profile to upgrade",
+            .description = "The path to the Nix profile to upgrade.",
             .labels = {"profile-dir"},
             .handler = {&profileDir}
         });
 
         addFlag({
             .longName = "nix-store-paths-url",
-            .description = "URL of the file that contains the store paths of the latest Nix release",
+            .description = "The URL of the file that contains the store paths of the latest Nix release.",
             .labels = {"url"},
             .handler = {&storePathsUrl}
         });

src/nix/verify.cc

@@ -18,13 +18,13 @@ struct CmdVerify : StorePathsCommand
 
     CmdVerify()
     {
-        mkFlag(0, "no-contents", "do not verify the contents of each store path", &noContents);
+        mkFlag(0, "no-contents", "Do not verify the contents of each store path.", &noContents);
-        mkFlag(0, "no-trust", "do not verify whether each store path is trusted", &noTrust);
+        mkFlag(0, "no-trust", "Do not verify whether each store path is trusted.", &noTrust);
 
         addFlag({
             .longName = "substituter",
             .shortName = 's',
-            .description = "use signatures from specified store",
+            .description = "Use signatures from the specified store.",
             .labels = {"store-uri"},
             .handler = {[&](std::string s) { substituterUris.push_back(s); }}
         });
@@ -32,7 +32,7 @@ struct CmdVerify : StorePathsCommand
         addFlag({
             .longName = "sigs-needed",
             .shortName = 'n',
-            .description = "require that each path has at least N valid signatures",
+            .description = "Require that each path has at least *n* valid signatures.",
             .labels = {"n"},
             .handler = {&sigsNeeded}
         });

src/nix/why-depends.cc

@@ -40,7 +40,7 @@ struct CmdWhyDepends : SourceExprCommand
         addFlag({
             .longName = "all",
             .shortName = 'a',
-            .description = "show all edges in the dependency graph leading from 'package' to 'dependency', rather than just a shortest path",
+            .description = "Show all edges in the dependency graph leading from *package* to *dependency*, rather than just a shortest path.",
             .handler = {&all, true},
         });
     }