Also allow this function to be called without arguments, in which case,
don't call error at all. Some uses of this function wrongly assumed
that this was already allowed.

Signed-off-by: Dave Reisner <dreisner@archlinux.org>
Signed-off-by: Pierre Schmitz <pierre@archlinux.de>

Reduces code duplication.

With makechrootpkg not calling mkarchroot anymore,
the lock handover protocol is unneeded.

arch-nspawn does not do any locking, so add protection to archbuild.

Stop trap_exit from forcing a 0 exit code. This fixes makechrootpkg,
which used to always return success, even if the build failed.

Signed-off-by: Pierre Schmitz <pierre@archlinux.de>

* Honor TMPDIR variable (just like we did in commit a0c6bf45

).
* Quote path properly.
* Avoid unnecessary use of basename(1).

Signed-off-by: Lukas Fleischer <archlinux@cryptocrack.de>
Signed-off-by: Pierre Schmitz <pierre@archlinux.de>

Signed-off-by: Lukas Fleischer <archlinux@cryptocrack.de>
Signed-off-by: Pierre Schmitz <pierre@archlinux.de>

* common.sh is included on build time
* most functions are copied from makepkg