February 2021

Notes on porting a JAN code check-digit validation script from ASP.NET / JavaScript to PHP, with a working PHP sample.

Install ChromeDriver 126 on Ubuntu 22.04 and run Selenium against it — apt + manual download steps, plus matching the Chromium / Chrome version.

Set the system timezone of Alpine Linux to JST (Asia/Tokyo), including how to do it inside a Dockerfile.

When building a Docker image on a Mac, you might encounter the "no space left on device" error. This can happen even when there seems to be enough storage space available, leaving you puzzled about the cause.

Fix compile errors when installing Python's `grpcio` — workarounds for missing C++ headers and CFLAGS adjustments to make `pip install grpcio` succeed.

Fix screen redraw issues when Mac Quick Look or Finder content is displayed on a DisplayLink-connected screen.

Inspect `django-redis` cached values directly from `manage.py shell` — both `cache.get` and the raw Redis client commands.