slicer/test: Define all release archives

Currently the slicer test defines one archive named "ubuntu" for all
test cases no matter what they define in chisel.yaml. But since commit
afad3d2 we allow more archives with different names to be defined in
chisel.yaml. Define a test archive for each of them.

internal/slicer/slicer_test.go

@@ -487,6 +487,35 @@ var slicerTests = []slicerTest{{
 		`,
 	},
 	error: `slice base-files_myslice: content is not a file: /x/y`,
+}, {
+	summary: "Non-default archive",
+	slices:  []setup.SliceKey{{"base-files", "myslice"}},
+	release: map[string]string{
+		"chisel.yaml": `
+			format: chisel-v1
+			archives:
+				foo:
+					version: 22.04
+					components: [main, universe]
+					default: true
+				bar:
+					version: 22.04
+					components: [main]
+		`,
+		"slices/mydir/base-files.yaml": `
+			package: base-files
+			archive: bar
+			slices:
+				myslice:
+					contents:
+						/usr/bin/hello:
+		`,
+	},
+	result: map[string]string{
+		"/usr/":          "dir 0755",
+		"/usr/bin/":      "dir 0755",
+		"/usr/bin/hello": "file 0775 eaf29575",
+	},
 }}
 
 const defaultChiselYaml = `
@@ -549,11 +578,13 @@ func (s *S) TestRun(c *C) {
 			c.Assert(err, IsNil)
 			pkgs[name] = deb
 		}
-		archives := map[string]archive.Archive{
-			"ubuntu": &testArchive{
+		archives := map[string]archive.Archive{}
+		for name, _ := range release.Archives {
+			archive := &testArchive{
 				arch: test.arch,
 				pkgs: pkgs,
-			},
+			}
+			archives[name] = archive
 		}
 
 		targetDir := c.MkDir()