builder - allow automatic switching to different remote branch

ENV variables __builder_repo && __builder_branch are used to switch to another repository/branch for building.

This is used to more easily build binaries before branches are merged into master. Primarily for SDL binaries, but simplifies testing for other modules.

Author: joolswills

scriptmodules/admin/builder.sh

@@ -127,7 +127,24 @@ function chroot_build_builder() {
             mkdir -p "$scriptdir/$archive_dir" "$chroot_rps_dir/$archive_dir"
             rsync -av "$scriptdir/$archive_dir/" "$chroot_rps_dir/$archive_dir/"
         else
-            rp_callModule image chroot "$chroot_dir" git -C /home/pi/RetroPie-Setup pull
+            rp_callModule image chroot "$chroot_dir" bash -c "
+                cd ~/RetroPie-Setup
+                git checkout master
+                git pull
+                if git remote | grep -q builder; then
+                    git branch -D builder-branch
+                    git remote remove builder
+                fi
+            "
+            # if we have a __builder_repo and __builder_branch set, check out the branch and use that
+            if [[ -n "$__builder_repo" && "$__builder_branch" ]]; then
+                rp_callModule image chroot "$chroot_dir" bash -c "
+                    cd ~/RetroPie-Setup
+                    git remote add builder $__builder_repo
+                    git fetch -q builder
+                    git checkout builder/$__builder_branch -b builder-branch
+                    "
+            fi
         fi
 
         for platform in $platforms; do