This is the first step in creating this repository from the legacy openbsc.git.
Like all other Osmocom repositories, keep the autoconf and automake files in
the repository root. openbsc.git has been the sole exception, which ends now.
We are building with libosmo-sccp tag 'old_sua' until the new sigtran has
been applied. Since osmo-iuh commit
"migrate osmo-hnbgw to libosmo-sigtran's SCCP/M3UA"
osmo-iuh requires libosmo-sccp master. A similar 'old_sua' tag is in place in
osmo-iuh.git, to match libosmo-sccp 'old_sua'. Do that to fix the jenkins
build of --enable-iu.
Have a bash function to build each dependency with the same commands. There is
a tradeoff: having each dependency build with the same function means you can't
easily tweak one of the dependencies. OTOH having a unified function means a)
more readable script, b) that we're sure not to forget some steps and c) no
need to do the same edit n times.
Set the PKG_CONFIG_PATH globally. Also a tradeoff: if a future addition
wouldn't need the same PKG_CONFIG_PATH, this would make things ugly. But that
is actually quite unlikely, and the readability improvement is substantial.
Use env variables to remember local paths. That means we always are sure to cd
to the same absolute base path, which a 'cd ..' can't guarantee; also, we avoid
possible typos for e.g. "$deps/install".