Merge pull request #6449 from edolstra/outputs-spec

Allow selecting derivation outputs

6 files changed, 73 insertions, 15 deletions

diff --git a/src/nix/bundle.cc b/src/nix/bundle.cc
index 2421adf4e..2e48e4c74 100644
--- a/src/nix/bundle.cc
+++ b/src/nix/bundle.cc
@@ -75,10 +75,10 @@ struct CmdBundle : InstallableCommand
 
         auto val = installable->toValue(*evalState).first;
 
-        auto [bundlerFlakeRef, bundlerName] = parseFlakeRefWithFragment(bundler, absPath("."));
+        auto [bundlerFlakeRef, bundlerName, outputsSpec] = parseFlakeRefWithFragmentAndOutputsSpec(bundler, absPath("."));
         const flake::LockFlags lockFlags{ .writeLockFile = false };
         InstallableFlake bundler{this,
-            evalState, std::move(bundlerFlakeRef), bundlerName,
+            evalState, std::move(bundlerFlakeRef), bundlerName, outputsSpec,
             {"bundlers." + settings.thisSystem.get() + ".default",
              "defaultBundler." + settings.thisSystem.get()
             },
diff --git a/src/nix/develop.cc b/src/nix/develop.cc
index 7fc74d34e..1190b8348 100644
--- a/src/nix/develop.cc
+++ b/src/nix/develop.cc
@@ -507,6 +507,7 @@ struct CmdDevelop : Common, MixEnvironment
                 state,
                 installable->nixpkgsFlakeRef(),
                 "bashInteractive",
+                DefaultOutputs(),
                 Strings{},
                 Strings{"legacyPackages." + settings.thisSystem.get() + "."},
                 nixpkgsLockFlags);
diff --git a/src/nix/flake.cc b/src/nix/flake.cc
index 6a34ca67b..1938ce4e6 100644
--- a/src/nix/flake.cc
+++ b/src/nix/flake.cc
@@ -724,7 +724,7 @@ struct CmdFlakeInitCommon : virtual Args, EvalCommand
         auto [templateFlakeRef, templateName] = parseFlakeRefWithFragment(templateUrl, absPath("."));
 
         auto installable = InstallableFlake(nullptr,
-            evalState, std::move(templateFlakeRef), templateName,
+            evalState, std::move(templateFlakeRef), templateName, DefaultOutputs(),
             defaultTemplateAttrPaths,
             defaultTemplateAttrPathsPrefixes,
             lockFlags);
diff --git a/src/nix/nix.md b/src/nix/nix.md
index 0dacadee6..d48682a94 100644
--- a/src/nix/nix.md
+++ b/src/nix/nix.md
@@ -146,6 +146,51 @@ For most commands, if no installable is specified, the default is `.`,
 i.e. Nix will operate on the default flake output attribute of the
 flake in the current directory.
 
+## Derivation output selection
+
+Derivations can have multiple outputs, each corresponding to a
+different store path. For instance, a package can have a `bin` output
+that contains programs, and a `dev` output that provides development
+artifacts like C/C++ header files. The outputs on which `nix` commands
+operate are determined as follows:
+
+* You can explicitly specify the desired outputs using the syntax
+  *installable*`^`*output1*`,`*...*`,`*outputN*. For example, you can
+  obtain the `dev` and `static` outputs of the `glibc` package:
+
+  ```console
+  # nix build 'nixpkgs#glibc^dev,static'
+  # ls ./result-dev/include/ ./result-static/lib/
+  …
+  ```
+
+* You can also specify that *all* outputs should be used using the
+  syntax *installable*`^*`. For example, the following shows the size
+  of all outputs of the `glibc` package in the binary cache:
+
+  ```console
+  # nix path-info -S --eval-store auto --store https://cache.nixos.org 'nixpkgs#glibc^*'
+  /nix/store/g02b1lpbddhymmcjb923kf0l7s9nww58-glibc-2.33-123                 33208200
+  /nix/store/851dp95qqiisjifi639r0zzg5l465ny4-glibc-2.33-123-bin             36142896
+  /nix/store/kdgs3q6r7xdff1p7a9hnjr43xw2404z7-glibc-2.33-123-debug          155787312
+  /nix/store/n4xa8h6pbmqmwnq0mmsz08l38abb06zc-glibc-2.33-123-static          42488328
+  /nix/store/q6580lr01jpcsqs4r5arlh4ki2c1m9rv-glibc-2.33-123-dev             44200560
+  ```
+
+* If you didn't specify the desired outputs, but the derivation has an
+  attribute `meta.outputsToInstall`, Nix will use those outputs. For
+  example, since the package `nixpkgs#libxml2` has this attribute:
+
+  ```console
+  # nix eval 'nixpkgs#libxml2.meta.outputsToInstall'
+  [ "bin" "man" ]
+  ```
+
+  a command like `nix shell nixpkgs#libxml2` will provide only those
+  two outputs by default.
+
+* Otherwise, Nix will use all outputs of the derivation.
+
 # Nix stores
 
 Most `nix` subcommands operate on a *Nix store*.
diff --git a/src/nix/profile-install.md b/src/nix/profile-install.md
index e3009491e..aed414963 100644
--- a/src/nix/profile-install.md
+++ b/src/nix/profile-install.md
@@ -20,6 +20,13 @@ R""(
   # nix profile install nixpkgs/d73407e8e6002646acfdef0e39ace088bacc83da#hello
   ```
 
+* Install a specific output of a package:
+
+  ```console
+  # nix profile install nixpkgs#bash^man
+  ```
+
+
 # Description
 
 This command adds *installables* to a Nix profile.
diff --git a/src/nix/profile.cc b/src/nix/profile.cc
index 52c918016..685776bec 100644
--- a/src/nix/profile.cc
+++ b/src/nix/profile.cc
@@ -22,13 +22,13 @@ struct ProfileElementSource
     // FIXME: record original attrpath.
     FlakeRef resolvedRef;
     std::string attrPath;
-    // FIXME: output names
+    OutputsSpec outputs;
 
     bool operator < (const ProfileElementSource & other) const
     {
         return
-            std::pair(originalRef.to_string(), attrPath) <
-            std::pair(other.originalRef.to_string(), other.attrPath);
+            std::tuple(originalRef.to_string(), attrPath, outputs) <
+            std::tuple(other.originalRef.to_string(), other.attrPath, other.outputs);
     }
 };
 
@@ -42,7 +42,7 @@ struct ProfileElement
     std::string describe() const
     {
         if (source)
-            return fmt("%s#%s", source->originalRef, source->attrPath);
+            return fmt("%s#%s%s", source->originalRef, source->attrPath, printOutputsSpec(source->outputs));
         StringSet names;
         for (auto & path : storePaths)
             names.insert(DrvName(path.name()).name);
@@ -98,7 +98,7 @@ struct ProfileManifest
             auto version = json.value("version", 0);
             std::string sUrl;
             std::string sOriginalUrl;
-            switch(version){
+            switch (version) {
                 case 1:
                     sUrl = "uri";
                     sOriginalUrl = "originalUri";
@@ -116,11 +116,12 @@ struct ProfileManifest
                 for (auto & p : e["storePaths"])
                     element.storePaths.insert(state.store->parseStorePath((std::string) p));
                 element.active = e["active"];
-                if (e.value(sUrl,"") != "") {
-                    element.source = ProfileElementSource{
+                if (e.value(sUrl, "") != "") {
+                    element.source = ProfileElementSource {
                         parseFlakeRef(e[sOriginalUrl]),
                         parseFlakeRef(e[sUrl]),
-                        e["attrPath"]
+                        e["attrPath"],
+                        e["outputs"].get<OutputsSpec>()
                     };
                 }
                 elements.emplace_back(std::move(element));
@@ -156,6 +157,7 @@ struct ProfileManifest
                 obj["originalUrl"] = element.source->originalRef.to_string();
                 obj["url"] = element.source->resolvedRef.to_string();
                 obj["attrPath"] = element.source->attrPath;
+                obj["outputs"] = element.source->outputs;
             }
             array.push_back(obj);
         }
@@ -283,10 +285,11 @@ struct CmdProfileInstall : InstallablesCommand, MixDefaultProfile
             if (auto installable2 = std::dynamic_pointer_cast<InstallableFlake>(installable)) {
                 // FIXME: make build() return this?
                 auto [attrPath, resolvedRef, drv] = installable2->toDerivation();
-                element.source = ProfileElementSource{
+                element.source = ProfileElementSource {
                     installable2->flakeRef,
                     resolvedRef,
                     attrPath,
+                    installable2->outputsSpec
                 };
             }
 
@@ -443,6 +446,7 @@ struct CmdProfileUpgrade : virtual SourceExprCommand, MixDefaultProfile, MixProf
                     getEvalState(),
                     FlakeRef(element.source->originalRef),
                     "",
+                    element.source->outputs,
                     Strings{element.source->attrPath},
                     Strings{},
                     lockFlags);
@@ -454,10 +458,11 @@ struct CmdProfileUpgrade : virtual SourceExprCommand, MixDefaultProfile, MixProf
                 printInfo("upgrading '%s' from flake '%s' to '%s'",
                     element.source->attrPath, element.source->resolvedRef, resolvedRef);
 
-                element.source = ProfileElementSource{
+                element.source = ProfileElementSource {
                     installable->flakeRef,
                     resolvedRef,
                     attrPath,
+                    installable->outputsSpec
                 };
 
                 installables.push_back(installable);
@@ -513,8 +518,8 @@ struct CmdProfileList : virtual EvalCommand, virtual StoreCommand, MixDefaultPro
         for (size_t i = 0; i < manifest.elements.size(); ++i) {
             auto & element(manifest.elements[i]);
             logger->cout("%d %s %s %s", i,
-                element.source ? element.source->originalRef.to_string() + "#" + element.source->attrPath : "-",
-                element.source ? element.source->resolvedRef.to_string() + "#" + element.source->attrPath : "-",
+                element.source ? element.source->originalRef.to_string() + "#" + element.source->attrPath + printOutputsSpec(element.source->outputs) : "-",
+                element.source ? element.source->resolvedRef.to_string() + "#" + element.source->attrPath + printOutputsSpec(element.source->outputs) : "-",
                 concatStringsSep(" ", store->printStorePathSet(element.storePaths)));
         }
     }