New alr printenv --last-build

This may be useful when no direct editing of manifests is convenient, as
otherwise `printenv` will always use the manifest's configuration.

src/alr/alr-commands-printenv.adb

@@ -1,3 +1,4 @@
+with Alire.Crate_Configuration;
 with Alire.Environment;
 with Alire.Platforms;
 
@@ -29,6 +30,11 @@ package body Alr.Commands.Printenv is
 
       Cmd.Requires_Workspace;
 
+      if Cmd.Last_Build then
+         Cmd.Root.Set_Build_Profiles
+           (Alire.Crate_Configuration.Last_Build_Profiles);
+      end if;
+
       declare
          Context : constant Alire.Environment.Context :=
                      Cmd.Root.Build_Context;
@@ -89,6 +95,10 @@ package body Alr.Commands.Printenv is
                      Cmd.Cmd_Shell'Access,
                      "", "--wincmd",
                      "Use a Windows CMD shell format for the export");
+      Define_Switch (Config,
+                     Cmd.Last_Build'Access,
+                     "", "--last-build",
+                     "Use last build profiles instead of manifest profiles");
    end Setup_Switches;
 
 end Alr.Commands.Printenv;

src/alr/alr-commands-printenv.ads

@@ -36,5 +36,6 @@ private
       Unix_Shell  : aliased Boolean := False;
       Power_Shell : aliased Boolean := False;
       Cmd_Shell   : aliased Boolean := False;
+      Last_Build  : aliased Boolean := False;
    end record;
 end Alr.Commands.Printenv;

testsuite/drivers/builds.py

@@ -9,6 +9,13 @@
 from drivers.alr import alr_builds_dir, run_alr
 
 
+def clear_builds_dir() -> None:
+    """
+    Clear the shared build directory
+    """
+    rmtree(path())
+
+
 def enable_shared() -> None:
     """
     Enable shared builds
@@ -88,4 +95,4 @@ def sync() -> None:
         pass
 
 def sync_builds() -> None:
-    sync()
+    sync()

testsuite/tests/printenv/last-build/test.py

@@ -0,0 +1,34 @@
+"""
+Test that `alr printenv --last-build` works as expected.
+"""
+
+from drivers import builds
+from drivers.alr import alr_with, init_local_crate, run_alr
+from drivers.asserts import assert_match
+
+builds.enable_shared()
+
+init_local_crate()
+alr_with("libhello")
+run_alr("build")
+
+# After a default build, we obtain the hash of the build in release mode
+hash_release = builds.find_hash("libhello")
+
+builds.clear_builds_dir()
+
+# Now obtain the hash of the build in development mode
+run_alr("build", "--profiles=*=development")
+hash_devel = builds.find_hash("libhello")
+
+assert hash_release != hash_devel, "Hashes should be different"
+
+# Check default printenv behavior
+p = run_alr("printenv")
+assert_match(f".*LIBHELLO_ALIRE_PREFIX=[^\n]*{hash_release}", p.out)
+
+# Check printenv --last-build behavior
+p = run_alr("printenv", "--last-build")
+assert_match(f".*LIBHELLO_ALIRE_PREFIX=[^\n]*{hash_devel}", p.out)
+
+print("SUCCESS")

testsuite/tests/printenv/last-build/test.yaml

@@ -0,0 +1,3 @@
+driver: python-script
+indexes:
+    build_hash_index: {}