race condition with -j# in Makefile

[thestinger]

Build log: http://sprunge.us/VNBW

note: /usr/bin/ld: cannot find -lrustrt

[thestinger]

occurs on both i686 and x86_64, very strange

[pnkfelix]

sequence of events leading to the failure, drawn from the log strcat posted, I think

link: x86_64-unknown-linux-gnu/rt/stage0/librustrt.so
link: x86_64-unknown-linux-gnu/rt/stage1/librustrt.so
link: x86_64-unknown-linux-gnu/rt/stage2/librustrt.so
cp: x86_64-unknown-linux-gnu/stage0/lib/rustc/x86_64-unknown-linux-gnu/lib/librustrt.so
cp: x86_64-unknown-linux-gnu/stage1/lib/librustrt.so
cp: x86_64-unknown-linux-gnu/stage1/lib/rustc/x86_64-unknown-linux-gnu/lib/librustrt.so
cp: x86_64-unknown-linux-gnu/stage2/lib/librustrt.so
cp: x86_64-unknown-linux-gnu/stage2/lib/rustc/x86_64-unknown-linux-gnu/lib/librustrt.so

removing x86_64-unknown-linux-gnu/stage0/lib/rustc/x86_64-unknown-linux-gnu/lib/librustrt.so
extracting rust-stage0/lib/librustrt.so

The steps that copy librustrt into the target directory are supposed to wait until the snapshot unpacking script is done downloading and unpacking, because the unpacking script cleans out the target area of "old products" before it copies its contents over.

I'll try to fix this in the makefile dependencies. But maybe its time for me to consider changing the script to not clean out the contents of stageN/lib/rustc/*/lib/. Not sure.

[thestinger]

@pnkfelix: I'll try unsetting MAKEFLAGS to verify

[pnkfelix]

I've replicated locally on my OS X machine with these steps:

% rm -rf *
% ../configure --enable-debug --enable-optimize  --enable-ccache --enable-clang --prefix=~/opt/rust-dbg
%  remake --trace -j16
...
note: ld: library not found for -lmorestack
clang: error: linker command failed with exit code 1 (use -v to see invocation)

error: aborting due to previous error
remake: *** [x86_64-apple-darwin/stage0/lib/rustc/x86_64-apple-darwin/lib/libstd.dylib] Error 101
Command-line invocation:
    "/Users/pnkfelix/opt-remake/bin/remake --trace -j16"

(and the same ordering, with the copy librustrt.dylib preceding the unpacking of the snapshot, takes place for me as well.)

[thestinger]

Edited the title to reflect the actual bug.