How to extract signal from almost useless error message

[jacg]

@7c6f434c

What else do you expect this to say?

Adjusting for the specifc hashes used in the example, I expect it to say

hash mismatch in fixed-output derivation '/nix/store/hhvgs3wwribfvkgdff7pmfnb4vy801bs-channel-rust-nightly.toml.drv':
  specified: sha256-hTj47PwUeP276uF6+HLDzsHYoDvfJa+y9o+vmxZqV0Y=
     got:    sha256-hTj47PwUeP276uF6+HLDzsHYoDvfJa+y9o+vmxZqV0g=

… which is exactly what it says in identical situations in a slightly different context … and I still haven’t got to the bottom of what exactly the context change is which turns the message from spot-on to almost useless.

@7c6f434c

Still a hack, of course, as you are using nightly procedures for stable releases,

If you can suggest a better solution to this problem, I’d be most grateful.