No store path created when one (recursive-)fixed-output-derivation references another

[nagy]

Describe the bug

When referencing one fixed-output-derivation whithin another, the resulting store path is not created and no error is printed.

Steps To Reproduce
Run nix-build on this file:

with import <nixpkgs> { };
runCommandLocal "name" {
  outputHashMode = "recursive";
  outputHash = "sha256-dUgGNFqVR0sCLzjDNAvfJJegR95Zpg/r+6i32P5/TlM=";
} ''
  mkdir $out
  echo ${emptyFile} > $out/somefile
''

The output would be

this derivation will be built:
  /nix/store/hcdh67622vpp9lwc9y6camyh0lbijpi9-name.drv
building '/nix/store/hcdh67622vpp9lwc9y6camyh0lbijpi9-name.drv'...
/nix/store/l1qz2gphlwmldkmgakzk581mhm0g0g5k-name

and the result symlink is created, but the underlying store path does not exist.

Expected behavior

A result stored in the nix-store.

nix-env --version output

nix-env (Nix) 2.11.0

Additional context

I have seen #5509 , but it may not be the same as that one seems to relate to self-reference.

One more thing: If specify the output to be a flat file instead of a directory, like so:

with import <nixpkgs> { };
runCommandLocal "name" {
  outputHashMode = "flat";
  outputHash = "sha256-AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=";
} ''
  echo ${emptyFile} > $out
''

I get:

$ nix-build
this derivation will be built:
  /nix/store/xcbn6gpxj8rqyc7sqancfj0913am6z7v-name.drv
building '/nix/store/xcbn6gpxj8rqyc7sqancfj0913am6z7v-name.drv'...
error: unexpected end-of-file

I think these two issues are related, but if not, I can file a separate one.