bug#37499: Wrong location of deps directory when using AC_SUBST

[Fabrizio Bertocci]

Karl,

Sorry for the late reply.

Here are the sequence of the commands that show the issue described:

Test use of relative path to identify external lib:

$ tar xfz autotool-bug-rel.tar.gz

$ cd autotool-bug/proj

$ ./bootstrap.sh

$ ./configure --with-mylib=../lib

$ make

$ ls -la src/.deps              # Note the testApp-main.Po

$ ls -la ../lib                 # Note the .deps and .dirstamp

$ ls -la ../lib/.deps           # Note the testApp-mylib_log.Po and .dirstamp

$ cd ../..

$ mv autotool-bug autotool-bug-rel  # Move it out of the way

------------------------------

Test use of absolute path to identify external lib:

$ tar xfz autotool-bug-abs.tar.gz

$ cd autotool-bug/proj

$ ./bootstrap.sh

$ ./configure --with-mylib=../lib

$ make

Making all in src

make[1]: Entering directory '/home/fabrizio/temp/autotool-bug/proj/src'

Makefile:353: /home/fabrizio/temp/autotool-bug/lib/.deps/testApp-mylib_log.Po: No such file or directory

make[1]: *** No rule to make target '/home/fabrizio/temp/autotool-bug/lib/.deps/testApp-mylib_log.Po'.  Stop.

make[1]: Leaving directory '/home/fabrizio/temp/autotool-bug/proj/src'

Makefile:331: recipe for target 'all-recursive' failed

make: *** [all-recursive] Error 1

$ ls -la src

total 72
drwxr-xr-x 4 fabrizio fabrizio  4096 Dec  7 07:33 .
drwxr-xr-x 4 fabrizio fabrizio  4096 Dec  7 07:33 ..
drwxr-xr-x 2 fabrizio fabrizio  4096 Dec  7 07:33 .deps
drwxr-xr-x 3 fabrizio fabrizio  4096 Dec  7 07:33 home               ###### ???????
-rw-r--r-- 1 fabrizio fabrizio    83 Sep 24  2019 main.c
-rw-r--r-- 1 fabrizio fabrizio 22554 Dec  7 07:33 Makefile
-rw-r--r-- 1 fabrizio fabrizio   106 Nov 24 14:01 Makefile.am
-rw-r--r-- 1 fabrizio fabrizio 22001 Dec  7 07:33 Makefile.in

--------------------------------

Differences between the two use case:

$ diff configure.ac ../../autotool-bug-rel/proj/configure.ac

28c28

< dnl MYLIB_PATH=`realpath --relative-to src "${MYLIB_PATH}"`

---

> MYLIB_PATH=`realpath --relative-to src "${MYLIB_PATH}"`

31c31

< MYLIB_PATH=`readlink -f ${MYLIB_PATH}`

---

> dnl MYLIB_PATH=`readlink -f ${MYLIB_PATH}`

In the 'relative path' case, MYLIB_PATH uses realpath to calculate ../lib relative to the 'src' directory. 

In the 'absolute path' case, MYLIB_PATH contains the full absolute path of the ../lib.

Note that in the 'absolute path' case, there is a new 'home' directory under 'src'  containing the full tree to the .Po file from the library.

Just try to run those commands and unless is something simple to address, please close the ticket and let's move on. 

I understand that this situation is not really a representative use case and is not supported.

Regards,

Fabrizio

On Sat, Nov 28, 2020 at 9:46 PM Karl Berry <karl@freefriends.org> wrote:

Hi Fabrizio - unfortunately, your examples work for me, in that I can
run, in the proj/ directory, either
./configure --with-mylib=../lib
or
./configure --with-mylib=/abs/path/to/autotool-bug/lib

and then make, in either the proj/ directory or the proj/src
subdirectory, and it all completes successfully.
All this with both your tarballs. So I remain unclear as to what you're
doing. Sorry.

Since configure is run in the proj/ directory, not proj/src, it seems
evident that any method, absolute or relative, which specifies mylib to
be the ../../lib directory cannot work, because that directory will not
exist relative to proj/.

Can you tell me exactly what commands you are running, starting with
tar xf <tarfile> (and which <tarfile> to use), to see the problem?
Just one sequence to reproduce the problem is enough.

    a wrong directory: proj/src/home/fabrizio/test/lib/.deps

In any event, this blind concatenation of paths surely looks
wrong. Maybe if the path (whatever it is) is absolute, the concatenation
should be avoided.

Unfortunately, I cannot discern where the computations are happening,
whether it's somewhere in the depcomp script or the Makefile that's
calling it.

In addition, I agree with Hans-Bernhard that using a directory outside
of top_srcdir is not exactly supported, although evidently it works in
some cases. Even if it cannot be handled properly, perhaps a real error
message could be given, or at least the deficiency documented.

Thanks,
Karl