It's possible to put a path into the store in pure mode by pretending
it's locked like this:
$ echo 'lalala' > testfile
$ nix eval --expr '(builtins.fetchTree { path = "/home/ma27/testfile"; rev = "0000000000000000000000000000000000000000"; type = "path"; })'
{ lastModified = 1723656303; lastModifiedDate = "20240814172503"; narHash = "sha256-hOMY06A0ohaaCLwnhpZIMoAqi/8kG2vk30NRiqi0dfc="; outPath = "/nix/store/lhfz259iipmv9ky995rml8018jvriynh-source"; rev = "0000000000000000000000000000000000000000"; shortRev = "0000000"; }
$ cat /nix/store/lhfz259iipmv9ky995rml8018jvriynh-source
lalala
There was a fix in CppNix[1], but Puck noted that it's breaking
backwards-compatibility because
> [...] a github fetch with a fully specified rev is no longer considered "locked"
> this is for "purity" reasons, but it breaks any existing flake.nix files
I tried a way smaller correctness fix here:
* Each scheme can denote whether a `rev` is enough to consider itself
locked.
* If a `rev` is given and the scheme is OK with just a `rev` to be
locked, the input is marked as locked.
For `path` this is not the case anymore, i.e. it requires a NAR hash to
be locked down.
[1] https://github.com/nixos/nix/commit/071dd2b3a4e6c0b2106f1b6f14ec26e153d97446
Change-Id: Ibbbf4733c82bcfa1c24dfe099a896d8aaecd81cc
Maximilian Bosch
62fb98ae55