Precompiling indirect dependencies causes `LoadError: Unknown package`

[omus]

In Julia 1.12.1 I noticed that using Pkg.precompile on a indirect package dependency results in the exception LoadError: Unknown package: <pkg-name>.

❯ JULIA_DEPOT_PATH=/tmp/depot JULIA_PKG_PRECOMPILE_AUTO=0 julia +1.12.1 --project=/tmp/project -e 'using Pkg; Pkg.add("ODBC")'
Precompiling Pkg finished.
  1 dependency successfully precompiled in 69 seconds
  Installing known registries into `/tmp/depot`
       Added `General` registry to /tmp/depot/registries
    Updating registry at `/tmp/depot/registries/General.toml`
   Resolving package versions...
   Installed IteratorInterfaceExtensions ─ v1.0.0
   Installed Readline_jll ──────────────── v8.2.13+0
   Installed DecFP ─────────────────────── v1.4.1
   Installed DataValueInterfaces ───────── v1.0.0
   Installed OrderedCollections ────────── v1.8.1
   Installed LogExpFunctions ───────────── v0.3.29
   Installed Scratch ───────────────────── v1.3.0
   Installed SpecialFunctions ──────────── v2.6.1
   Installed iODBC_jll ─────────────────── v3.52.16+0
   Installed unixODBC_jll ──────────────── v2.3.12+0
   Installed DecFP_jll ─────────────────── v2.0.300+0
   Installed OpenSpecFun_jll ───────────── v0.5.6+0
   Installed Ncurses_jll ───────────────── v6.5.1+0
   Installed IrrationalConstants ───────── v0.2.6
   Installed DataAPI ───────────────────── v1.16.0
   Installed Tables ────────────────────── v1.12.1
   Installed JLLWrappers ───────────────── v1.7.1
   Installed Libiconv_jll ──────────────── v1.18.0+0
   Installed TableTraits ───────────────── v1.0.1
   Installed ODBC ──────────────────────── v1.1.2
   Installed DBInterface ───────────────── v2.6.1
   Installed Preferences ───────────────── v1.5.0
   Installed DocStringExtensions ───────── v0.9.5
  Installing artifacts ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 7/7
    Updating `/private/tmp/project/Project.toml`
  [be6f12e9] + ODBC v1.1.2
    Updating `/private/tmp/project/Manifest.toml`
  [a10d1c49] + DBInterface v2.6.1
  [9a962f9c] + DataAPI v1.16.0
  [e2d170a0] + DataValueInterfaces v1.0.0
  [55939f99] + DecFP v1.4.1
  [ffbed154] + DocStringExtensions v0.9.5
  [92d709cd] + IrrationalConstants v0.2.6
  [82899510] + IteratorInterfaceExtensions v1.0.0
  [692b3bcd] + JLLWrappers v1.7.1
  [2ab3a3ac] + LogExpFunctions v0.3.29
  [be6f12e9] + ODBC v1.1.2
  [bac558e1] + OrderedCollections v1.8.1
  [21216c6a] + Preferences v1.5.0
  [6c6a2e73] + Scratch v1.3.0
  [276daf66] + SpecialFunctions v2.6.1
  [3783bdb8] + TableTraits v1.0.1
  [bd369af6] + Tables v1.12.1
  [47200ebd] + DecFP_jll v2.0.300+0
  [94ce4f54] + Libiconv_jll v1.18.0+0
  [68e3532b] + Ncurses_jll v6.5.1+0
  [efe28fd5] + OpenSpecFun_jll v0.5.6+0
  [05236dd9] + Readline_jll v8.2.13+0
  [80337aba] + iODBC_jll v3.52.16+0
  [1841a5aa] + unixODBC_jll v2.3.12+0
  [56f22d72] + Artifacts v1.11.0
  [ade2ca70] + Dates v1.11.0
  [8f399da3] + Libdl v1.11.0
  [37e2e46d] + LinearAlgebra v1.12.0
  [de0858da] + Printf v1.11.0
  [9a3f8284] + Random v1.11.0
  [ea8e919c] + SHA v0.7.0
  [fa267f1f] + TOML v1.0.3
  [cf7118a7] + UUIDs v1.11.0
  [4ec0a83e] + Unicode v1.11.0
  [e66e0078] + CompilerSupportLibraries_jll v1.3.0+1
  [4536629a] + OpenBLAS_jll v0.3.29+0
  [05823500] + OpenLibm_jll v0.8.7+0
  [8e850b90] + libblastrampoline_jll v5.15.0+0
    Building ODBC → `/tmp/depot/scratchspaces/44cfe95a-1eb2-52ea-b672-e2afdf69b78f/7fe19bed38551e3169edaec8bb8673354d355681/build.log`

❯ JULIA_DEPOT_PATH=/tmp/depot JULIA_PKG_PRECOMPILE_AUTO=0 julia +1.12.1 --project=/tmp/project -e 'using Pkg; Pkg.precompile("DecFP")'
ERROR: Unknown package: DecFP

The issue did not appear in Julia 1.12.0. I believe this issue was introduced as a side effect from the changes introduced in #59212.

[omus]

If we decide that we do not want to support manually triggering precompilation on indirect dependencies we should at least ensure that the error reported provides the user is clearer.

[KristofferC]

As soon as you talk about indirect dependencies you kind of need to have a UUID as well since you can have many indirect dependencies with the same name.