Added --preserve-environment to su invocation.

Author: HackingM

.gentoo/coverage.sh

@@ -2,7 +2,8 @@
 
 useradd -m -G users -s /bin/bash testrunner
 
-su - testrunner -c "kcov --bash-dont-parse-binary-dir \
+su --preserve-environment testrunner -c \
+    "kcov --bash-dont-parse-binary-dir \
      --include-path=. \
      /var/tmp/coverage \
      bats -t tests"