Bruno Haible wrote: > Jim Meyering wrote: >> I noticed this build failure for grep: >> >> http://hydra.nixos.org/build/329919 >> >> CCLD grep >> Undefined symbols: >> "_rpl_open", referenced from: >> _grepfile in grep.o >> ld: symbol(s) not found >> collect2: ld returned 1 exit status >> make[2]: *** [grep] Error 1 >> >> I fixed it with this change to grep, and do appreciate >> the implied warning that grep needs the "open" module, >> but this must be a bug in gnulib... >> ... >> * bootstrap.conf (gnulib_modules): Using gnulib's fcntl module >> and including <fcntl.h>, but not also using gnulib's "open" module >> would result in link failure due to references to rpl_open >> on systems requiring the replacement (e.g., Cygwin and Darwin). > > I wouldn't say that it's a bug in gnulib. The situation in the 'grep' > package is as follows: > - The main part, in lib/, has the module 'fcntl' and therefore > implicitly 'fcntl-h', but not the 'open' module. > - The tests part, in gnulib-tests/, has the module 'open', as a > dependency from 'dup2-tests'. > - The presence of the 'open' module is indicated through an > AC_SUBSTed variable GNULIB_OPEN. There is only one GNULIB_OPEN > for the entire package, and it is set to 1. > - Therefore the lib/fcntl.h replacement defines "#define open rpl_open". > > It's a limitation of gnulib that you cannot decide to not use a module in > the main part but use it in the tests. If you really wanted that, you > would need a setup with two different configure.ac files, one for the > main part and one for the tests.
I see your point: in a way it's my own fault for making grep's gnulib-tests/ share the same headers and library used for the rest of the package. Nonetheless, in that situation it would be nice to have a way to ensure that the primary module list is a superset of those used for the tests. Offhand, I don't see how to obtain the test-induced list of modules. Of course, what I really would like is the difference of the transitive closure of the test-induced module set and the TC of the primary module list.
