This is partial revert of 8454daa7fe (makepkg: run pkgver() and
prepare() with --noextract).
Reasoning for the reversion (copied from FS#43498):
Running prepare() when --noextract is used no longer allows running
'makepkg -o && makepkg -e' with any PKGBUILD that applies patches in
prepare(). [1]
Sure there's --noprepare which restores the old behavior, but that's
a lot of extra typing for what I believe is a much more common use
of --noextract.
For OP's use case of doing git bisects, you can specify the commit
in the source array and thus skip --noextract since makepkg will
checkout the correct commit each time.
[1] I often extract the sources using 'makepkg -o', manually edit
some source files, and then use 'makepkg -e' to package it (while
possibly repeating the edit/package steps).
Signed-off-by: Allan McRae <allan@archlinux.org>