`make install` starts rebuilding stage0 after a just completed `make`

jurily ~/p/e/rust $ rm -rf build
jurily ~/p/e/rust $ mkdir build; and cd build
jurily ~/p/e/r/build $ ../configure --enable-fast-make --prefix=~/sys/
configure: looking for configure programs
<snip>
jurily ~/p/e/r/build $ smake
cfg: build triple x86_64-unknown-linux-gnu
cfg: host triples x86_64-unknown-linux-gnu
<snip>
oxidize: x86_64-unknown-linux-gnu/stage2/lib/rustlib/x86_64-unknown-linux-gnu/lib/librustdoc
67m 11s jurily ~/p/e/r/build $ make install
cfg: build triple x86_64-unknown-linux-gnu
cfg: host triples x86_64-unknown-linux-gnu
cfg: target triples x86_64-unknown-linux-gnu
cfg: enabling more debugging (CFG_ENABLE_DEBUG)
cfg: host for x86_64-unknown-linux-gnu is x86_64
cfg: os for x86_64-unknown-linux-gnu is unknown-linux-gnu
cfg: using gcc
cfg: no node found, omitting docs
cfg: including prepare rules
cfg: including install rules
oxidize: x86_64-unknown-linux-gnu/stage0/lib/rustlib/x86_64-unknown-linux-gnu/lib/libstd

[adrientetar]

cc @brson

[brson]

I'll look at this.

[brson]

I haven't been able to reproduce this with just make; make install.

I can't repro either, with any config. Closing.

make install runs configure again, which does the submodule thing, and if upstream pushed a new commit during the build, it invalidates everything.

[brson]

So much has changed I assume this is fixed. If not feel free to reopen.