case "$target_os" in
should be before confvars.sh call, not after.
Created attachment 562609 [details] [diff] [review]
(Av1) Remove a redundant and misplaced MOZ_INSTALLER=1 block
[Checked in: Comment 3]
I was going to move this block up,
but bug 557824 made MOZ_INSTALLER=1 as default,
then this block can just be removed.
(That bug should have done this.)