QTC: cache get_env results for improved performance

It turns out that QUtil::get_env is particularly expensive on Windows
if there is a large environment. This may be true on other platforms
as well.

1 files changed, 2 insertions, 0 deletions

diff --git a/TODO b/TODO
index d4824cc6..fc007c98 100644
--- a/TODO
+++ b/TODO
@@ -10,6 +10,8 @@ Before Release:
   * Cache environment variables
   * Remove coverage cases for things that are heavily exercised or are
     in critical paths
+* Make ./performance_check usable by other people by having published
+  files to use for testing.
 * Evaluate issues tagged with `next`
 * Stay on top of https://github.com/pikepdf/pikepdf/pull/315