Test

alire.toml

@@ -78,7 +78,7 @@ commit = "9a9c660f9c6f27f5ef75417e7fac7061dff14d78"
 
 [pins.ncdu]
 url    = "https://github.com/mosteo/ncdu-ada.git"
-commit = "d444b5f48d5cfe89079bc507a2320eb898cf6bfa"
+commit = "89f6deec1815b8b27ea906aeb51b323336122868"
 
 [pins.semantic_versioning]
 url    = "https://github.com/alire-project/semantic_versioning"

src/alire/alire-cache.adb

@@ -106,8 +106,11 @@ package body Alire.Cache is
       end Usage_Wrap;
 
    begin
-      --  The root node should be the cache dir itself
-      if Tree.Length not in 1 then
+      --  The root node should be the cache dir itself, unless there is still
+      --  no cache at all.
+      if Tree.Is_Empty then
+         return Item_Sets.Empty_Set;
+      elsif Tree.Length not in 1 then
          raise Program_Error
            with "Cache tree root length /= 1:" & Tree.Length'Image;
       end if;

src/alr/alr-commands-cache.adb

@@ -11,6 +11,7 @@ package body Alr.Commands.Cache is
    procedure Summary is
       use Alire.Directories;
       Table : Alire.Utils.Tables.Table;
+      Usage : constant Alire.Cache.Usages := Alire.Cache.Usage;
    begin
       Table
         .Append ("Path:")
@@ -19,7 +20,9 @@ package body Alr.Commands.Cache is
 
       Table
         .Append ("Size:")
-        .Append (TTY_Image (Alire.Cache.Usage.First_Element.Size));
+        .Append (TTY_Image (if Usage.Is_Empty
+                            then 0
+                            else Alire.Cache.Usage.First_Element.Size));
 
       Table.Print (Trace.Always);
    end Summary;

testsuite/tests/cache/summary/test.py

@@ -0,0 +1,37 @@
+"""
+Check the basic report of cache use
+"""
+
+from drivers import builds
+from drivers.alr import run_alr, init_local_crate, alr_with
+from drivers.asserts import assert_match
+
+# Default cache status after clean install
+
+assert_match("""\
+Path:.*alr-config/cache
+Size: 0.0 B
+""",
+run_alr("cache").out)
+
+# Compile something with a dependency and there should be something in the
+# cache when builds are shared.
+
+init_local_crate()
+alr_with("libhello")
+run_alr("build")
+p = run_alr("cache")
+if builds.are_shared():
+    # Something already in the cache
+    assert_match(r"Path:.*alr-config/cache\nSize: (?!0.0 B).*\n", p.out)
+else:
+    # Still nothing if no shared cache
+    assert_match(r"Path:.*alr-config/cache\nSize: 0.0 B\n", p.out)
+
+# After installing some toolchain, for sure there should be something in the cache
+
+run_alr("toolchain", "--select", "gnat_native=1", "gprbuild")
+p = run_alr("cache")
+assert_match(r"Path:.*alr-config/cache\nSize: (?!0.0 B).*\n", p.out)
+
+print("SUCCESS")

testsuite/tests/cache/summary/test.yaml

@@ -0,0 +1,5 @@
+driver: python-script
+build_mode: both
+indexes:
+    gnat_toolchain_index: {}
+    basic_index: {}