Revert "Merge pull request #11804 from obsidiansystems/remove-old-make"

This reverts commit 619eeb658a, reversing
changes made to 1af94bf471.

tests/functional/common/functions.sh

@@ -343,6 +343,15 @@ count() {
   echo $#
 }
 
+# Sometimes, e.g. due to pure eval, restricted eval, or sandboxing, we
+# cannot look up `config.nix` in the build dir, and have to instead get
+# it from the current directory. (In this case, the current directly
+# will be somewhere in `$TEST_ROOT`.)
+removeBuildDirRef() {
+  # shellcheck disable=SC2016 # The ${} in this is Nix, not shell
+  sed -i -e 's,"${builtins.getEnv "_NIX_TEST_BUILD_DIR"}/[^ ]*config.nix",./config.nix,' "$@"
+}
+
 trap onError ERR
 
 fi # COMMON_FUNCTIONS_SH_SOURCED