So, `aclocal` has a flag to control this behavior: specifically, its
`--install` flag. Right now I don't see `aclocal` mentioned in the GNU
Coding Standards at all. Should they be updated to include a
recommendation as to whether it's better to put `--install` in
`ACLOCAL_AMFLAGS` or not? Or would such a recommendation be a better
fit for the `automake` manual (since that's where `aclocal` comes
from)?
A common scenario is that the embedded M4 files are not the
latest version and that the code in configure.ac is not compatible
with newer versions that might be installed. Setting the --install
flag and make every developer bootstrap with 'aclocal --install'
or anyone trying to bootstrap an old version of the project would
be very fragile. Also 'aclocal --install' only overwrite the
embedded copy if the serial numbers in the files suggest the
installed file is a newer version than the embedded M4 file.