version.h is essential for building, and its generation was done by a
shell script. Strictly speaking, python should in general be more
portable (windows), and would be better for the upcoming meson build to
simply just execute a python script. version.py has some small
differences with version.sh which shouldn't matter but they are noted
below.
- version.sh accepted several arguments that seemed useless (like
--cwd). These were removed from version.py.
- version.py takes either no arguments (prints the version) or it takes
exactly one argument specifying the complete path of where the header
should be generated.
- version.sh attempted to read a file named "snapshot_version". The
comments noted that this was for "daily tarball snapshots". Such a
file does not exist in the source tree, and it's not really clear that
anyone actually uses this. This logic was removed from version.py.
- version.py reads the SOURCE_DATE_EPOCH environment variable. Some
distros use this for reproducible builds. Technically you could also
just disable the build date but this is only a couple of extra lines
and maybe it's prettier than UNKNOWN.
- version.py also doesn't attempt to display timezone information in the
build date. It only shows UTC time.
Kacper Michajłow