mc: Fragile bootstrap (was cp: cannot stat 'obj/mbld/mbld': No such file or directory)

• https://github.com/oridb/mc/commit/a819f7ccdc3ed6c63f50f23c0b17fa478604d821

Building after a clean clone with the following:

% ./configure --prefix=/usr
% make -j4 bootstrap            # This happens without -j4 as well

Yields a new error:

[...]
+ ar -rcs obj/lib/regex/libregex.a obj/lib/regex/interp.o obj/lib/regex/ranges.o obj/lib/regex/types.o obj/lib/regex/compile.o
+ /home/earnest/build/staging/myrddin-git/src/mc/muse/muse -o obj/lib/regex/libregex.use -p regex obj/lib/regex/interp.use obj/lib/regex/ranges.use obj/lib/regex/types.use obj/lib/regex/compile.use
+ /home/earnest/build/staging/myrddin-git/src/mc/6/6m -O obj -I obj/lib/sys -I obj/lib/std -I obj/lib/bio -I obj/lib/regex -I obj/lib/thread mbld/subtest.myr
+ /home/earnest/build/staging/myrddin-git/src/mc/6/6m -O obj -I obj/lib/sys -I obj/lib/std -I obj/lib/bio -I obj/lib/regex -I obj/lib/thread mbld/test.myr
+ /home/earnest/build/staging/myrddin-git/src/mc/6/6m -O obj -I obj/lib/sys -I obj/lib/std -I obj/lib/bio -I obj/lib/regex -I obj/lib/thread mbld/deps.myr
+ /home/earnest/build/staging/myrddin-git/src/mc/6/6m -O obj -I obj/lib/sys -I obj/lib/std -I obj/lib/bio -I obj/lib/regex -I obj/lib/thread mbld/main.myr
+ ld --gc-sections -o obj/mbld/mbld /home/earnest/build/staging/myrddin-git/src/mc/rt/_myrrt.o obj/mbld/deps.o obj/mbld/main.o obj/mbld/util.o obj/mbld/cpufeatures.o obj/mbld/libs.o obj/mbld/syssel.o obj/mbld/config.o obj/mbld/opts.o obj/mbld/subtest.o obj/mbld/types.o obj/mbld/test.o obj/mbld/install.o obj/mbld/parse.o obj/mbld/build.o -Lobj/lib/thread -lthread -Lobj/lib/bio -lbio -Lobj/lib/regex -lregex -Lobj/lib/std -lstd -Lobj/lib/sys -lsys
ld: cannot find -lthread
ld: cannot find -lstd
ld: cannot find -lsys
+ true
cp obj/mbld/mbld xmbld
cp: cannot stat 'obj/mbld/mbld': No such file or directory
make: *** [Makefile;26: bootstrap] Error 1

Interestingly, if I run make bootstrap again, it completes without issue.