[pondidum]

Only read the flag once! For multiple flags we tend to have the first step in the build read all flags we care about and export them to environment variables.

[verdverm]

How do you enforce that they are only read upfront?

Why not just make them parameters if you are going to put them upfront and turn them into ENVs?

How do you deal with a commit that needs to be rerun? What if the flags have changed in between?