Hello Marc, Thanks for the report.
* Marc Espie wrote on Thu, Dec 27, 2007 at 05:29:37PM CET: > On Thu, Dec 27, 2007 at 05:25:56PM +0100, Marc Espie wrote: > > the mkdir -p macro arbitrarily restricts itself to GNU mkdir by passing > > it a --version. Not arbitrarily. > > This is a bit offensive. No, it is defensive: that's a mkdir implementation known to be race free. > > On OpenBSD, this particular issue does not exist. > > It was fixed 8 years ago, published as OpenBSD 2.4, and all newer > > versions are not affected. Oh well, OpenBSD mkdir had a different race I reported 18 months ago (PR user/5141). It seems someone fixed it in OpenBSD's CVS just today, see <http://www.openbsd.org/cgi-bin/cvsweb/src/bin/mkdir/mkdir.c>. If you were involved in the process, then thanks for doing so. > > Could we get an OS test and use mkdir on OpenBSD >= 2.4, please ? Maybe two years after an OpenBSD release is out that has the above issue fixed. I suppose though that the added complexity of pulling in the AC_CANONICAL_BUILD tests is not worth the trouble. > Turns out the install_sh -d stuff is NOT safe in parallel mode, it errors out > while trying to create a directory that already exists. Now, this is interesting. Could you provide the script_version of the install-sh script of the package that exposes this, and also a 'make -jX' output of a failure? Ideally, I'd like to see a 'set -x' output of the script failure, but don't bother if it's difficult to expose the race that way. Note there was a race condition present inside install-sh which was fixed on 2006-05-11; this race could lead to a failure if -m is used and the mode change is required in order for a subsequent mkdir to have sufficient privileges to create an inner directory. See <http://lists.gnu.org/archive/html/automake-patches/2006-05/msg00063.html> and references therein for the discussion. Since you don't mention privilege problems, I assume it is unrelated to the issue you observed. > In general, most autoconf/automake tests DO set a cache entry, and you > can later rely on that entry. This can be useful for package builders: > we could very easily force configure to use mkdir -p, if we know we've > got a safe one. But no, this test is done again and again for each > configure entry. With Autoconf >= 2.60 and Automake >= 1.10, this test is done by the Autoconf macro AC_PROG_MKDIR_P, and you can use the variable $MKDIR_P (and the cache variable is ac_cv_path_mkdir). 'install' is searched for by AC_PROG_INSTALL, overridden by $INSTALL, and cached in ac_cv_path_install. Hope that helps. Happy New Year. Cheers, Ralf
