[BUG] spec.CargohomeDeps may return nil which will cause debug.Cargohome to panic

[invidian]

Expected Behavior

All scenarios to be handled gracefully.

Actual Behavior

With input like this:

diff --git test/source_test.go test/source_test.go
index fd6732f..94de109 100644
--- test/source_test.go
+++ test/source_test.go
@@ -760,7 +760,6 @@ index ea874f5..ba38f84 100644
                                stat, err := ref.StatFile(ctx, gwclient.StatRequest{
                                        Path: dep,
                                })
-
                                if err != nil {
                                        t.Fatal(err)
                                }
@@ -990,18 +989,18 @@ func TestSourceWithCargohome(t *testing.T) {
                const contextName = "multi-cargo-module"
                spec := &dalec.Spec{
                        Name: "test-dalec-cargo-context-source",
-                       Sources: map[string]dalec.Source{
-                               "src": {
-                                       Context: &dalec.SourceContext{Name: contextName},
-                                       Generate: []*dalec.SourceGenerator{
-                                               {
-                                                       Cargohome: &dalec.GeneratorCargohome{
-                                                               Paths: []string{"./dir/module1", "./dir/module2"},
+                       /*                      Sources: map[string]dalec.Source{
+                                               "src": {
+                                                       Context: &dalec.SourceContext{Name: contextName},
+                                                       Generate: []*dalec.SourceGenerator{
+                                                               {
+                                                                       Cargohome: &dalec.GeneratorCargohome{
+                                                                               Paths: []string{"./dir/module1", "./dir/module2"},
+                                                                       },
+                                                               },
                                                        },
                                                },
-                                       },
-                               },
-                       },
+                                       },*/
                        Dependencies: &dalec.PackageDependencies{
                                Build: map[string]dalec.PackageConstraints{
                                        "rust": {

Panic occurs:

        runtime.panicmem
        	runtime/panic.go:262
        runtime.sigpanic
        	runtime/signal_unix.go:925
        github.com/project-dalec/dalec/frontend/debug.Cargohome.func1
        	github.com/project-dalec/dalec/frontend/debug/handle_cargohome.go:39
        github.com/project-dalec/dalec/frontend.BuildWithPlatformFromUIClient.func1
        	github.com/project-dalec/dalec/frontend/build.go:159
        github.com/moby/buildkit/frontend/dockerui.(*Client).Build.func1
        	github.com/moby/buildkit@v0.25.2/frontend/dockerui/build.go:39
        golang.org/x/sync/errgroup.(*Group).Go.func1
        	golang.org/x/sync@v0.18.0/errgroup/errgroup.go:93
        runtime.goexit
        	runtime/asm_amd64.s:1693

Steps To Reproduce

1. Modify tests as mentioned.
2. Run tests as go test -run SourceWithCargohome/multi-module ./test

Are you willing to submit PRs to contribute to this bug fix?

• Yes, I am willing to implement it.

[cpuguy83]

I think this is fixed now?

[invidian]

It's not.

dalec/generator_cargohome.go

Line 76 in bcf5538

return nil

still returns nil and frontend here

dalec/frontend/debug/handle_cargohome.go

Line 38 in bcf5538

st := spec.CargohomeDeps(sOpt, worker, dalec.Platform(platform), pg)

does not check it.