This pull request has been mentioned on NixOS Discourse. There might be relevant details there:

https://discourse.nixos.org/t/prs-already-reviewed/2617/65

@timokau There isn't an upstream issue (I will create one), and the patch is mandatory, because the version detection does not work fine.

Why doesn't it work fine? Are you sure it wasn't intended to check for 5.1?

In any case, please add a comment explaining this (and a link to the upstream issue after creating it) to the file.

@timokau I did that

@timokau that work for me:
nix-prefetch-url "https://savannah.gnu.org/patch/download.php?file_id=47859"

[0.0 MiB DL]

path is '/nix/store/zib4ckh512pm5366ab0zg0q2ggp0wc7q-download.php?file_id=47859'

1bwi50qr7wlf8dm3bf7clnly0l69v3nk8gh9h8pdlnhsb52d311j

Can confirm hash mismatch:

100   426  100   426    0     0    432      0 --:--:-- --:--:-- --:--:--   432
hash mismatch in fixed-output derivation '/nix/store/0av5md9blfybkbb6czsv84kd4rmfhn24-download.php?file_id=47859':
  wanted: sha256:1bwi50qr7wlf8dm3bf7clnly0l69v3nk8gh9h8pdlnhsb52d311j
  got:    sha256:0aimayzgi5065gkcfcr8d5lkd9c0471q7dqmln42hjzq847n6d5y

@marius851000: Keep in mind that if you used nix-prefetch-url or something like that, you'd have a cached version in your store, but fetchpatch normalizes the patch and so the checksum actually turns out to be different.

I get the same hash as @marius851000. This is pretty strange.

I get the same hash as @marius851000. This is pretty strange.

@rnhmjoj: With nix-prefetch-url or actually running it through fetchpatch? See my remark above regarding nix-prefetch-url - its a common pitfall with fetchpatch;

> nix repl '<nixpkgs>'

nix-repl> :b fetchpatch { url = "https://savannah.gnu.org/patch/download.php?file_id=47859"; sha256 = lib.fakeSha256; }
hash mismatch in fixed-output derivation '/nix/store/0av5md9blfybkbb6czsv84kd4rmfhn24-download.php?file_id=47859':
  wanted: sha256:0000000000000000000000000000000000000000000000000000
  got:    sha256:0aimayzgi5065gkcfcr8d5lkd9c0471q7dqmln42hjzq847n6d5y
[0 built (1 failed), 1 copied (0.2 MiB), 0.1 MiB DL]
error: build of '/nix/store/p1nl81nks7943yyr2m61q4kkkcw6g090-download.php?file_id=47859.drv' failed

While with nix-prefetch-url, I get the hash you are expecting - but as outlined, this is the hash before fetchpatch applies its normalizations, but it will still work for you, because nix-prefetch-url adds it to the local store and then fetchpatch never even gets executed;

>  nix-prefetch-url "https://savannah.gnu.org/patch/download.php?file_id=47859"                                                                                 master [ad8c1703ec5] untracked
[0.0 MiB DL]
path is '/nix/store/zib4ckh512pm5366ab0zg0q2ggp0wc7q-download.php?file_id=47859'
1bwi50qr7wlf8dm3bf7clnly0l69v3nk8gh9h8pdlnhsb52d311j

(Edit: added nix-prefetch-url paste, for clarification)

@timokau I fixed that. At least, I now know what fetchpath does.

@d-goldin You were right, I was using prefetch-url.

@GrahamcOfBorg build gnash

@timokau I fixed that. At least, I now know what fetchpath does.

Seems to still be the old/wrong hash and fails the checks: https://github.com/NixOS/nixpkgs/pull/73040/checks?check_run_id=311777285

@timokau You're right, sorry. I just haven't added my change to git.

Thanks!