bugfix: the wrong folder was searched for nested crates

We were attempting to enter a folder that not always will exist.

src/alire/alire-releases.adb

@@ -270,9 +270,16 @@ package body Alire.Releases is
                                  Paths.Working_Folder_Inside_Root
                                  / (Paths.Crate_File_Name & ".upstream");
             begin
+               --  Backup if already there
                Alire.Directories.Backup_If_Existing
                  (Upstream_File,
                   Base_Dir => Paths.Working_Folder_Inside_Root);
+               --  Remove just backed up file
+               if Directories.Is_File (Upstream_File) then
+                  Directories.Delete_Tree
+                    (Directories.Full_Name (Upstream_File));
+               end if;
+               --  And rename the original manifest into upstream
                Ada.Directories.Rename
                  (Old_Name => Paths.Crate_File_Name,
                   New_Name => Upstream_File);
@@ -299,9 +306,12 @@ package body Alire.Releases is
       Trace.Debug ("Deploying " & This.Milestone.TTY_Image
                    & " into " & TTY.URL (Folder));
 
-      --  Deploy if the target dir is not already there
+      --  Deploy if the target dir is not already there. We only skip for
+      --  releases that require a folder to be deployed; system releases
+      --  require the deploy attempt as the installation check is done by
+      --  the deployer.
 
-      if Completed.Exists then
+      if This.Origin.Is_Index_Provided and then Completed.Exists then
          Was_There := True;
          Trace.Detail ("Skipping checkout of already available " &
                          This.Milestone.Image);

src/alire/alire-roots.adb

@@ -3,7 +3,6 @@ with Ada.Unchecked_Deallocation;
 with Alire.Builds;
 with Alire.Conditional;
 with Alire.Dependencies.Containers;
-with Alire.Directories;
 with Alire.Environment.Loading;
 with Alire.Errors;
 with Alire.Flags;
@@ -757,9 +756,12 @@ package body Alire.Roots is
                  );
 
                --  If the release was newly deployed, we can inform about its
-               --  nested crates now.
+               --  nested crates now (if it has its own folder where nested
+               --  crates could be found).
 
-               if not Was_There and then not CLIC.User_Input.Not_Interactive
+               if Rel.Origin.Is_Index_Provided
+                 and then not Was_There
+                 and then not CLIC.User_Input.Not_Interactive
                then
                   Print_Nested_Crates (This.Release_Base (Rel.Name,
                                                           For_Deploy));
@@ -1435,7 +1437,7 @@ package body Alire.Roots is
             Rel : constant Releases.Release := Release (This, Crate);
          begin
             if not This.Requires_Build_Sync (Rel) then
-               return This.Release_Parent (Rel, For_Build) / Rel.Base_Folder;
+               return This.Release_Parent (Rel, For_Deploy) / Rel.Base_Folder;
             else
                case Usage is
                   when For_Deploy =>

src/alire/alire-roots.ads

@@ -7,6 +7,7 @@ private with Alire.Builds.Hashes;
 with Alire.Containers;
 with Alire.Crate_Configuration;
 with Alire.Dependencies.States;
+with Alire.Directories;
 limited with Alire.Environment;
 private with Alire.Lockfiles;
 with Alire.Paths;
@@ -333,7 +334,8 @@ package Alire.Roots is
    --  overwrite even if existing (so `alr update` can deal with any
    --  corner case).
 
-   procedure Print_Nested_Crates (Path : Any_Path);
+   procedure Print_Nested_Crates (Path : Any_Path)
+     with Pre => Directories.Is_Directory (Path);
    --  Look for nested crates below the given path and print a summary of
    --  path/milestone:description for each one found. Won't enter `alire` dirs.
 

testsuite/fixtures/system_index/gn/gnat_external/gnat_external-external.toml

@@ -0,0 +1,12 @@
+description = "GNAT is a compiler for the Ada programming language"
+name = "gnat_external"
+
+maintainers = ["[email protected]"]
+maintainers-logins = ["mosteo"]
+
+[[external]]
+kind = "version-output"
+# We look for make instead that should be always installed.
+version-command = ["make", "--version"]
+version-regexp = ".*Make ([\\d\\.]+).*"
+provides = "gnat"

testsuite/fixtures/system_index/index.toml

@@ -0,0 +1 @@
+version = "1.1"

testsuite/fixtures/system_index/ma/make/make-external.toml

@@ -0,0 +1,9 @@
+description = "Utility for directing compilation"
+name = "make"
+maintainers = ["[email protected]"]
+maintainers-logins = ["mylogin"]
+
+[[external]]
+kind = "version-output"
+version-command = ["make", "--version"]
+version-regexp = ".*Make ([\\d\\.]+).*"

testsuite/tests/with/system-crate/test.py

@@ -0,0 +1,10 @@
+"""
+Check that a system crate dependency can be added without issue
+"""
+
+from drivers.alr import init_local_crate, run_alr
+
+init_local_crate()
+run_alr("with", "make")
+
+print("SUCCESS")

testsuite/tests/with/system-crate/test.yaml

@@ -0,0 +1,4 @@
+driver: python-script
+build_mode: both  # one of shared, sandboxed, both (default)
+indexes:
+    system_index: {}