make clean is not enough for out-of-source builds

[antocuni]

Bug report

Bug description:

1. First, do a regular in-tree build:

cpython $ ./configure && make

2. Then, try to make an out-of-tree build:

cpython $ mkdir debug
cpython $ cd debug
cpython/debug $ ../configure --with-pydebug && make
[...]
Error: The source directory (..) is not clean
Building Python out of the source tree (in /home/antocuni/pypy/misc/cpython/debug) requires a clean source tree (/home/antocuni/pypy/misc/cpython/debug/..)
Try to run: make -C ".." clean

3. Now, if you try to run a top-level make clean as suggested, it's not enough:

cpytohn/debug $ make -C ".." clean
[...]
cpython/debug $ make
Error: The source directory (..) is not clean
Building Python out of the source tree (in /home/antocuni/pypy/misc/cpython/debug) requires a clean source tree (/home/antocuni/pypy/misc/cpython/debug/..)
Try to run: make -C ".." clean

(I also tried to cd .. && make clean).
The problem seems to be that check-clean-src checks for the presence of the ./python binary, which is not removed by make clean:
https://github.com/python/cpython/blob/982f1b7d6dc2f13b9607ce092e36e32972e3702c/debug/Makefile#L773-L785

If I remove it manually, the out-of-tree make works as expected

CPython versions tested on:

CPython main branch

Operating systems tested on:

Linux

Linked PRs

• gh-110704: Recommend distclean target over clean when source tree is not clean #112610

[SnoopJ]

I just had this problem while trying to run the WASI build using the script introduced by #112473, running make distclean resolved the problem.

Seems to me that the check target should recommend distclean instead of clean for the reasons you've identified.

[brettcannon]

Do note I put the cleanup under distclean because it was easiest. If someone is motivated enough they could potentially get it moved.

[SnoopJ]

Do note I put the cleanup under distclean because it was easiest. If someone is motivated enough they could potentially get it moved.

I opened #112610 because I think having a more helpful suggestion would probably be enough to resolve confusion for the case I ran into (i.e. hinting the user towards the alternate target they need). I don't know if it would be better to move this cleanup to another target, but the suggestion text is an easy change.