Re: Understanding #:substitutable? and #55231

[Morgan Arnold]

Hi all,

As a bit of an aside, I'm wondering if it wouldn't be possible to eliminate the 
possibility of even potential copyviols by a change to the `derivation` 
function? It currently sets environment variable for the builder daemon by 
setting `allowSubstitutes = 0` if `(not substitutable?)`. If 
non-substitutability were propagated by doing something like instead setting 
`allowSubstitutes = 0` if `(not substitutable?)` or if `(not (every 
substitutable-derivation? inputs))`, wouldn't this suffice to ensure that an 
initrd which contains non-substitutable inputs is properly marked 
non-substitutable?

It might be more correct to allow derivations built with non-substitutable 
native inputs to be substitutable nonetheless. The alternative seems like it 
could cause issues, in particular with the non-substitutable texlive package 
being used as a native input to build documentation.

Best,

Morgan