mvp

Change-Id: I4c49b1beba93bb50e8f8a107edc451affe08c3f7

src/nix/upgrade-nix.cc

@@ -1,5 +1,6 @@
 #include "command.hh"
 #include "common-args.hh"
+#include "logging.hh"
 #include "store-api.hh"
 #include "filetransfer.hh"
 #include "eval.hh"
@@ -15,6 +16,8 @@ struct CmdUpgradeNix : MixDryRun, StoreCommand
     Path profileDir;
     std::string storePathsUrl = "https://github.com/NixOS/nixpkgs/raw/master/nixos/modules/installer/tools/nix-fallback-paths.nix";
 
+    std::optional<Path> overrideStorePath;
+
     CmdUpgradeNix()
     {
         addFlag({
@@ -25,6 +28,13 @@ struct CmdUpgradeNix : MixDryRun, StoreCommand
             .handler = {&profileDir}
         });
 
+        addFlag({
+            .longName = "store-path",
+            .description = "A specific store path to upgrade Nix to",
+            .labels = {"store-path"},
+            .handler = {&overrideStorePath},
+        });
+
         addFlag({
             .longName = "nix-store-paths-url",
             .description = "The URL of the file that contains the store paths of the latest Nix release.",
@@ -59,12 +69,15 @@ struct CmdUpgradeNix : MixDryRun, StoreCommand
     {
         evalSettings.pureEval = true;
 
-        if (profileDir == "")
+        if (profileDir == "") {
             profileDir = getProfileDir(store);
+        }
+
+        auto canonProfileDir = canonPath(profileDir, true);
 
         printInfo("upgrading Nix in profile '%s'", profileDir);
 
-        auto storePath = getLatestNix(store);
+        StorePath storePath = getLatestNix(store);
 
         auto version = DrvName(storePath.name()).version;
 
@@ -89,13 +102,41 @@ struct CmdUpgradeNix : MixDryRun, StoreCommand
 
         stopProgressBar();
 
-        {
-            Activity act(*logger, lvlInfo, actUnknown,
-                fmt("installing '%s' into profile '%s'...", store->printStorePath(storePath), profileDir));
-            runProgram(settings.nixBinDir + "/nix-env", false,
-                {"--profile", profileDir, "-i", store->printStorePath(storePath), "--no-sandbox"});
+        auto const fullStorePath = store->printStorePath(storePath);
+
+        // Will be either nix-env or nix (for nix profile).
+        std::string upgradeCmd;
+        Strings upgradeArgs;
+
+        if (canonProfileDir.ends_with("user-environment")) {
+            upgradeCmd = settings.nixBinDir + "/nix-env";
+            upgradeArgs = {
+                "--profile",
+                this->profileDir,
+                "--install",
+                fullStorePath,
+                "--no-sandbox",
+            };
+        } else if (canonProfileDir.ends_with("profile")) {
+            upgradeCmd = settings.nixBinDir + "/nix";
+            upgradeArgs = {
+                "profile",
+                "install",
+                "--profile",
+                this->profileDir,
+                fullStorePath,
+                "--no-sandbox",
+            };
+        } else {
+            // No I will not use std::unreachable.
+            // That is undefined behavior if you're wrong.
+            // This will have a half-decent error message and coredump.
+            assert("unreachable" == nullptr);
         }
 
+        printTalkative("running %s %s", upgradeCmd, concatStringsSep(" ", upgradeArgs));
+        runProgram(upgradeCmd, false, upgradeArgs);
+
         printInfo(ANSI_GREEN "upgrade to version %s done" ANSI_NORMAL, version);
     }
 
@@ -121,26 +162,89 @@ struct CmdUpgradeNix : MixDryRun, StoreCommand
         Path profileDir = dirOf(where);
 
         // Resolve profile to /nix/var/nix/profiles/<name> link.
-        while (canonPath(profileDir).find("/profiles/") == std::string::npos && isLink(profileDir))
+        while (canonPath(profileDir).find("/profiles/") == std::string::npos && isLink(profileDir)) {
             profileDir = readLink(profileDir);
+        }
 
         printInfo("found profile '%s'", profileDir);
 
         Path userEnv = canonPath(profileDir, true);
 
-        if (baseNameOf(where) != "bin" ||
-            !userEnv.ends_with("user-environment"))
-            throw Error("directory '%s' does not appear to be part of a Nix profile", where);
+        if (baseNameOf(where) != "bin") {
+            if (!userEnv.ends_with("user-environment") && !userEnv.ends_with("profile")) {
+                throw Error("directory '%s' does not appear to be part of a Nix profile", where);
+            }
+        }
 
-        if (!store->isValidPath(store->parseStorePath(userEnv)))
+        if (!store->isValidPath(store->parseStorePath(userEnv))) {
             throw Error("directory '%s' is not in the Nix store", userEnv);
+        }
 
         return profileDir;
     }
 
+    void upgradeWithNixEnv(Store & store, StorePath const & newNix)
+    {
+        auto const fullStorePath = store.printStorePath(newNix);
+
+        // Starts the activity on construction and stops it on destruction.
+        Activity act(
+            *logger,
+            lvlInfo,
+            actUnknown,
+            fmt("installing '%s' into profile '%s'...", fullStorePath)
+        );
+
+        auto const nixEnv = settings.nixBinDir + "/nix-env";
+        Strings nixEnvArgs = {
+            "--profile",
+            this->profileDir,
+            "--install",
+            fullStorePath,
+            "--no-sandbox",
+        };
+
+        printTalkative("running %s %s", nixEnv, concatStringsSep(" ", nixEnvArgs));
+        runProgram(nixEnv, false, nixEnvArgs);
+    }
+
+    void upgradeWithNixProfile(Store & store, StorePath const & newNix)
+    {
+        auto const fullStorePath = store.printStorePath(newNix);
+
+        // Starts the activity on construction and stops it on destruction.
+        Activity act(
+            *logger,
+            lvlInfo,
+            actUnknown,
+            fmt("installing '%s' into profile '%s'...", fullStorePath, this->profileDir, this->profileDir)
+        );
+
+        auto const nixCmd = settings.nixBinDir + "/nix";
+        Strings nixCmdArgs = {
+            "profile",
+            "install",
+            "--profile",
+            this->profileDir,
+            fullStorePath,
+            "--no-sandbox",
+        };
+
+        printTalkative("running %s %s", nixCmd, concatStringsSep(" ", nixCmdArgs));
+        runProgram(nixCmd, false, nixCmdArgs);
+    }
+
     /* Return the store path of the latest stable Nix. */
     StorePath getLatestNix(ref<Store> store)
     {
+        if (this->overrideStorePath) {
+            printTalkative(
+                "skipping Nix version query and using '%s' as latest Nix",
+                *this->overrideStorePath
+            );
+            return store->parseStorePath(*this->overrideStorePath);
+        }
+
         Activity act(*logger, lvlInfo, actUnknown, "querying latest Nix version");
 
         // FIXME: use nixos.org?