From f15651303f8596bf34c67fc8d536b1e9e7843a87 Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <edolstra@gmail.com>
Date: Fri, 28 Aug 2020 19:24:29 +0200
Subject: [PATCH] nix develop: Add convenience flags for running specific
 phases

For example, for building the Nix flake, you would do:

  $ nix develop --configure
  $ nix develop --install
  $ nix develop --installcheck
---
 src/nix/develop.cc | 55 ++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 53 insertions(+), 2 deletions(-)

diff --git a/src/nix/develop.cc b/src/nix/develop.cc
index 20316c477..516e7bda9 100644
--- a/src/nix/develop.cc
+++ b/src/nix/develop.cc
@@ -264,6 +264,7 @@ struct Common : InstallableCommand, MixProfile
 struct CmdDevelop : Common, MixEnvironment
 {
     std::vector<std::string> command;
+    std::optional<std::string> phase;
 
     CmdDevelop()
     {
@@ -277,6 +278,43 @@ struct CmdDevelop : Common, MixEnvironment
                 command = ss;
             }}
         });
+
+        addFlag({
+            .longName = "phase",
+            .description = "phase to run (e.g. `build` or `configure`)",
+            .labels = {"phase-name"},
+            .handler = {&phase},
+        });
+
+        addFlag({
+            .longName = "configure",
+            .description = "run the configure phase",
+            .handler = {&phase, {"configure"}},
+        });
+
+        addFlag({
+            .longName = "build",
+            .description = "run the build phase",
+            .handler = {&phase, {"build"}},
+        });
+
+        addFlag({
+            .longName = "check",
+            .description = "run the check phase",
+            .handler = {&phase, {"check"}},
+        });
+
+        addFlag({
+            .longName = "install",
+            .description = "run the install phase",
+            .handler = {&phase, {"install"}},
+        });
+
+        addFlag({
+            .longName = "installcheck",
+            .description = "run the installcheck phase",
+            .handler = {&phase, {"installCheck"}},
+        });
     }
 
     std::string description() override
@@ -314,9 +352,22 @@ struct CmdDevelop : Common, MixEnvironment
 
         auto script = makeRcScript(buildEnvironment);
 
-        script +=  fmt("rm -f '%s'\n", rcFilePath);
+        if (verbosity >= lvlDebug)
+            script += "set -x\n";
 
-        if (!command.empty()) {
+        script += fmt("rm -f '%s'\n", rcFilePath);
+
+        if (phase) {
+            if (!command.empty())
+                throw UsageError("you cannot use both '--command' and '--phase'");
+            // FIXME: foundMakefile is set by buildPhase, need to get
+            // rid of that.
+            script += fmt("foundMakefile=1\n");
+            script += fmt("runHook %1%Phase\n", *phase);
+            script += fmt("exit 0\n", *phase);
+        }
+
+        else if (!command.empty()) {
             std::vector<std::string> args;
             for (auto s : command)
                 args.push_back(shellEscape(s));