change of libcompiler_builtins/lib.rs code doesn't retrigger a full rebuild anymore

[est31]

Before the recent changes to rustbuild, when changing libcompiler_builtins/lib.rs, it has rebuilt the entire stage0 artifacts and thus the entire compiler. Now its only doing:

    Finished debug [unoptimized] target(s) in 0.0 secs
Synchronisiere Submodul-URL für 'src/compiler-rt'
Synchronisiere Submodul-URL für 'src/jemalloc'
Synchronisiere Submodul-URL für 'src/liblibc'
Synchronisiere Submodul-URL für 'src/llvm'
Synchronisiere Submodul-URL für 'src/rt/hoedown'
Synchronisiere Submodul-URL für 'src/rust-installer'
HEAD ist jetzt bei a8fc4c1 Merge pull request #28 from xen0n/preprocessor-firefighting
HEAD ist jetzt bei e058ca6 Change how the default zone is found
HEAD ist jetzt bei e49e9bb Auto merge of #478 - jackpot51:patch-1, r=alexcrichton
HEAD ist jetzt bei ceb177e Merge pull request #60 from japaric/gh38406
HEAD ist jetzt bei a3736a0 Merge pull request #6 from intelfx/patch-1
HEAD ist jetzt bei 4f99485 Merge pull request #54 from brson/docdir
Building stage0 std artifacts (i686-unknown-linux-gnu -> i686-unknown-linux-gnu)
   Compiling compiler_builtins v0.0.0 (file://rust/src/libcompiler_builtins)
   Compiling std v0.0.0 (file://rust/src/libstd)
   Compiling std_shim v0.1.0 (file://rust/src/rustc/std_shim)
    Finished release [optimized] target(s) in 9.0 secs
Copying stage0 std from stage0 (i686-unknown-linux-gnu -> i686-unknown-linux-gnu / i686-unknown-linux-gnu)
Building stage0 test artifacts (i686-unknown-linux-gnu -> i686-unknown-linux-gnu)
    Finished release [optimized] target(s) in 0.0 secs
Copying stage0 test from stage0 (i686-unknown-linux-gnu -> i686-unknown-linux-gnu / i686-unknown-linux-gnu)
Building stage0 compiler artifacts (i686-unknown-linux-gnu -> i686-unknown-linux-gnu)
    Finished release [optimized] target(s) in 0.0 secs
Copying stage0 rustc from stage0 (i686-unknown-linux-gnu -> i686-unknown-linux-gnu / i686-unknown-linux-gnu)
Copying stage1 compiler (i686-unknown-linux-gnu)
Building stage1 std artifacts (i686-unknown-linux-gnu -> i686-unknown-linux-gnu)
   Compiling compiler_builtins v0.0.0 (file://rust/src/libcompiler_builtins)
   Compiling std v0.0.0 (file://rust/src/libstd)
   Compiling std_shim v0.1.0 (file://rust/src/rustc/std_shim)
    Finished release [optimized] target(s) in 10.10 secs
Copying stage1 std from stage1 (i686-unknown-linux-gnu -> i686-unknown-linux-gnu / i686-unknown-linux-gnu)
Building stage1 test artifacts (i686-unknown-linux-gnu -> i686-unknown-linux-gnu)
    Finished release [optimized] target(s) in 0.0 secs
Copying stage1 test from stage1 (i686-unknown-linux-gnu -> i686-unknown-linux-gnu / i686-unknown-linux-gnu)
Building stage1 compiler artifacts (i686-unknown-linux-gnu -> i686-unknown-linux-gnu)
    Finished release [optimized] target(s) in 0.0 secs
Copying stage1 rustc from stage1 (i686-unknown-linux-gnu -> i686-unknown-linux-gnu / i686-unknown-linux-gnu)
Copying stage2 compiler (i686-unknown-linux-gnu)
Copying stage2 std from stage1 (i686-unknown-linux-gnu -> i686-unknown-linux-gnu / i686-unknown-linux-gnu)
Copying stage2 test from stage1 (i686-unknown-linux-gnu -> i686-unknown-linux-gnu / i686-unknown-linux-gnu)
Building stage2 tool compiletest (i686-unknown-linux-gnu)
    Finished release [optimized] target(s) in 0.0 secs
Check compiletest suite=run-pass mode=run-pass (i686-unknown-linux-gnu -> i686-unknown-linux-gnu)

Later on, you are getting an error like "found possibly newer version of crate compiler_builtins which test depends on".

[est31]

cc @alexcrichton

note, I'm not using any --keep-stage stuff or anything.

[est31]

workaround is to do rm -rf build/TRIPLE/stage* manually

[alexcrichton]

I think this is the same as #38746 (or that's the same as this), haven't had a chance to investigate yet. My guess is that this is a regression from #38631

[est31]

@alexcrichton yes I think its the same issue. If you are closing dupes, then please close the one that was filed later :)