Merge pull request #6259 from Artturin/nixbuildaddprintstorepaths

nix build: add --print-out-paths flag

2 files changed, 31 insertions, 0 deletions

diff --git a/src/nix/build.cc b/src/nix/build.cc
index 840c7ca38..9c648d28e 100644
--- a/src/nix/build.cc
+++ b/src/nix/build.cc
@@ -4,6 +4,7 @@
 #include "shared.hh"
 #include "store-api.hh"
 #include "local-fs-store.hh"
+#include "progress-bar.hh"
 
 #include <nlohmann/json.hpp>
 
@@ -12,6 +13,7 @@ using namespace nix;
 struct CmdBuild : InstallablesCommand, MixDryRun, MixJSON, MixProfile
 {
     Path outLink = "result";
+    bool printOutputPaths = false;
     BuildMode buildMode = bmNormal;
 
     CmdBuild()
@@ -32,6 +34,12 @@ struct CmdBuild : InstallablesCommand, MixDryRun, MixJSON, MixProfile
         });
 
         addFlag({
+            .longName = "print-out-paths",
+            .description = "Print the resulting output paths",
+            .handler = {&printOutputPaths, true},
+        });
+
+        addFlag({
             .longName = "rebuild",
             .description = "Rebuild an already built package and compare the result to the existing store paths.",
             .handler = {&buildMode, bmCheck},
@@ -93,6 +101,22 @@ struct CmdBuild : InstallablesCommand, MixDryRun, MixJSON, MixProfile
                     }, buildable.raw());
                 }
 
+        if (printOutputPaths) {
+            stopProgressBar();
+            for (auto & buildable : buildables) {
+                std::visit(overloaded {
+                    [&](const BuiltPath::Opaque & bo) {
+                        std::cout << store->printStorePath(bo.path) << std::endl;
+                    },
+                    [&](const BuiltPath::Built & bfd) {
+                        for (auto & output : bfd.outputs) {
+                            std::cout << store->printStorePath(output.second) << std::endl;
+                        }
+                    },
+                }, buildable.raw());
+            }
+        }
+
         updateProfile(buildables);
     }
 };
diff --git a/src/nix/build.md b/src/nix/build.md
index 20138b7e0..6a79f308c 100644
--- a/src/nix/build.md
+++ b/src/nix/build.md
@@ -25,6 +25,13 @@ R""(
   lrwxrwxrwx 1 … result-1 -> /nix/store/rkfrm0z6x6jmi7d3gsmma4j53h15mg33-cowsay-3.03+dfsg2
   ```
 
+* Build GNU Hello and print the resulting store path.
+
+  ```console
+  # nix build nixpkgs#hello --print-out-paths
+  /nix/store/v5sv61sszx301i0x6xysaqzla09nksnd-hello-2.10
+  ```
+
 * Build a specific output:
 
   ```console