venv: BRANCH variable can be used as an override

This should make the testing of PRs before landing them more viable.

Signed-off-by: Rune Morling <[email protected]>

eopkg_venv_functions.bash

@@ -6,6 +6,9 @@ set -euo pipefail
 
 source shared_functions.bash
 
+# allow user to override branch name
+EOPKG_BRANCH="${BRANCH:-main}"
+
 function prepare_venv () {
     if [[ -z "${PY3}" ]]; then
         die "Couldn't find supported python3 (3.11 || 3.12 || 3.10) interpreter, exiting!"
@@ -15,7 +18,7 @@ function prepare_venv () {
     # Assume the user starts in the eopkg dir
     printInfo "Updating the eopkg git repo ..."
     # ensure we show the current branch
-    git fetch && git checkout main && git pull && git branch
+    git fetch && git checkout "${EOPKG_BRANCH}" && git pull && git branch
 
     printInfo "Set up a clean eopkg_venv venv ..."
     ${PY3} -m venv --system-site-packages --clear eopkg_venv