> One reason why some projects are discarding use of Autoconf (and moving to CMake and Meson/Ninja) is due to how long it takes to execute a configure script Slowest point, in my experience, is time for running testsuite anyway, then compile time. So, time to regenerate or rerun configure script is non-essential. The reason why I prefer meson nowadays is lack of proper support/detection of modern C and C++ standards/dialects by autoconf out of the box. The reason, why I keep autoconf for packages that already has it — the excellent autotest subsystem (AT_CHECK and Co). On Thu, Mar 12, 2020 at 11:04 PM Bob Friesenhahn < bfriesen@xxxxxxxxxxxxxxxxxxx> wrote: > On Thu, 12 Mar 2020, Zack Weinberg wrote: > > > > I agree in principle. > > > > On further investigation, there is a concrete reason why autoconf 2.69 > > prefers SHELL=/bin/bash to SHELL=/bin/dash, namely that dash doesn't > > support $LINENO, necessitating a complicated and fragile workaround > > (see _AS_LINENO_PREPARE in lib/m4sugar/m4sh.m4). This has been the > > behavior for a very long time (since roughly 2008). Moreover, the > > changed behavior of autoconf trunk was not intentional; it's because > > commit 2b59b6f8a79b8bf77e178ff4e5aa0ede433d39cf missed a direct use of > > $as_echo in _AS_DETECT_BETTER_SHELL, causing _AS_DETECT_BETTER_SHELL > > *not to work at all*! > > This is a good find. It explains a lot. > > > I'm still looking into why tests/testsuite malfunctions when run by > > dash, but right now I am inclined to say that the bug in > > _AS_DETECT_BETTER_SHELL should be fixed and then we should > > independently discuss whether it makes sense to prefer dash to bash. > > It *would* discourage people from writing bashisms in their > > configure.ac's and it *is* 30% faster than bash (on my computer, > > according to "time make check"), but not supporting $LINENO is a big > > loss. > > Years ago when we were investigating slowness of configure it was > determined that Bash is the "world's slowest shell" since it was > considerably slower than all other shells tested. The difference was > often more significant outside of GNU/Linux. This likely has not > changed. > > One reason why some projects are discarding use of Autoconf (and > moving to CMake and Meson/Ninja) is due to how long it takes to > execute a configure script. Given modern multicore CPUs, it often > takes as much (or more) time to run the configure script than to > compile the software. If configure can select the fastest shell which > works reliably, then Autoconf's reputation will improve. > > Bob > -- > Bob Friesenhahn > bfriesen@xxxxxxxxxxxxxxxxxxx, http://www.simplesystems.org/users/bfriesen/ > GraphicsMagick Maintainer, http://www.GraphicsMagick.org/ > Public Key, http://www.simplesystems.org/users/bfriesen/public-key.txt > > -- Andrew W. Nosenko <andrew.w.nosenko@xxxxxxxxx>
