Always validate that environment variables are properly defined and consistently named before using them in scripts or build processes. Undefined or misnamed variables can cause silent failures or unexpected behavior in builds and deployments.
Always validate that environment variables are properly defined and consistently named before using them in scripts or build processes. Undefined or misnamed variables can cause silent failures or unexpected behavior in builds and deployments.
Check for variable existence and provide meaningful defaults or error messages. Ensure variable names are consistent across different build environments (development, CI, packaging systems like Nix).
Example of problematic code:
# Bad: Using undefined variable
MESSAGE=$(git show ${GIT_COMMIT_HASH} | head -n 5 | tail -n 1)
# Better: Use defined variable or provide default
HASH=$(git rev-parse HEAD)
MESSAGE=$(git show ${HASH:-HEAD} | head -n 5 | tail -n 1)
Consider using build system features like CMake’s add_compile_definitions instead of shell script environment variable manipulation when possible, as build systems provide better validation and error handling.
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