@foone On Windows, you presumably get spaces in environment variable names presumably only by accident.But an actually cursed by design thing is that there are standard environment variables that have parentheses in their names, "ProgramFiles(Arm)" and "ProgramFiles(x86)". And then the build system for a certain complex open-source software (LibreOffice) actually needs the latter, but the way the build system is set up, it uses tools that import the environment in such a way that environment variables with cursed characters in their names get skipped...