Comma prints warning if you have a ~/.cache/nix-index/files

[hraban]

I used to index packages locally on my machine so I had a stale index lying around. This package's nix-locate ignored it, but comma gave a warning:

$ , hello
Warning: Nix-index database is older than 30 days, either obtain a prebuilt database from https://github.com/Mic92/nix-index-database or try updating with `nix run 'nixpkgs#nix-index' --extra-experimental-features 'nix-command flakes'`.
Hello, world!
$ which ,
/run/current-system/sw/bin/,
$ ls -l /run/current-system/sw/bin/,
lrwxr-xr-x  1 root  wheel  69 Dec 31  1969 /run/current-system/sw/bin/, -> /nix/store/0hrizv0a95g4rfhsg679506l976nb9xx-comma-with-db-1.7.1/bin/,
$ cat /run/current-system/sw/bin/,
#! /nix/store/0wzb184kckhmggq1nlvy5xk6rykp0jl1-bash-5.2-p21/bin/bash -e
export NIX_INDEX_DATABASE='/nix/store/0hrizv0a95g4rfhsg679506l976nb9xx-comma-with-db-1.7.1/share/cache/nix-index'
exec "/nix/store/25a77mrqczxqmsq6mrnbgqm25ra2lhyi-comma-1.7.1/bin/,"  "$@"
$ nix-locate -r '/bin/hello$'
haskellPackages.hello.out                    10,163,408 x /nix/store/y21zcncgd157xbb3bdnwqzai98h4x08r-hello-1.0.0.2/bin/hello
mbedtls.out                                     149,312 x /nix/store/s5zjq6hibgqbjx5xbcr50c5zkgrq8yl5-mbedtls-3.5.2/bin/hello
mbedtls_2.out                                    74,096 x /nix/store/1572c3fk6wvz0sd9rpahl9zg6iqjikrw-mbedtls-2.28.7/bin/hello
hello.out                                        82,256 x /nix/store/84ljc7x3vdlwnkmg3j65npz3dix188qq-hello-2.12.1/bin/hello
fltk14.bin                                            0 s /nix/store/y2xyqycdkhpqcz5paq3rwwksqlqibjjs-fltk-1.4.x-2021-12-21-bin/bin/hello
fltk.bin                                              0 s /nix/store/1i714kkqb4xz0r5vw4ggpqczfs2p562m-fltk-1.3.8-bin/bin/hello
$ # N.B.: no warning about nix DB being out of date
$ which nix-locate
/run/current-system/sw/bin/nix-locate
$ cat /run/current-system/sw/bin/nix-locate
#! /nix/store/0wzb184kckhmggq1nlvy5xk6rykp0jl1-bash-5.2-p21/bin/bash -e
export NIX_INDEX_DATABASE='/nix/store/wzc1ci0clv2lrp8nif9mr1479smz98as-nix-index-with-db-0.1.7/share/cache/nix-index'
exec "/nix/store/dx007v5i4jlm7mbx5rbrq8dmfxibgn96-nix-index-0.1.7/bin/nix-locate"  "$@"
$ ls -l /nix/store/0hrizv0a95g4rfhsg679506l976nb9xx-comma-with-db-1.7.1/share/cache/nix-index
total 0
lrwxr-xr-x  1 root  wheel  64 Dec 31  1969 files -> /nix/store/6cicbjx5q739a7x6xzklsclgcggc83rb-index-aarch64-darwin
$ ls -l /nix/store/wzc1ci0clv2lrp8nif9mr1479smz98as-nix-index-with-db-0.1.7/share/cache/nix-index
total 0
lrwxr-xr-x  1 root  wheel  64 Dec 31  1969 files -> /nix/store/6cicbjx5q739a7x6xzklsclgcggc83rb-index-aarch64-darwin
$ ls -lha ~/.cache/nix-index/files
-rw-r--r--@ 1 user  staff    31M Oct 17 13:02 /Users/user/.cache/nix-index/files
$ trash ~/.cache/nix-index/files
$ , hello
Hello, world!

Notice the warning after the first , hello, but none after the last.

[Mic92]

Ah. I saw this issue as well, but never investigated where it comes from.

[hraban]

NGL I ignored this warning for a long time until I accidentally figured it out 😂

[Mic92]

This is how we are currently wrapping things:

 export NIX_INDEX_DATABASE='/nix/store/4jscilyjg0vk8m21kw4blb9fb892b96v-comma-with-db-1.7.1/share/cache/nix-index'
 exec "/nix/store/cv9pya3qj1sqkxqlcj8qc7pqxmp8fc6h-comma-1.7.1/bin/,"  "$@" 

Comma should really prioritize NIX_INDEX_DATABASE over local files.

[Mic92]

Mhm. It's actually only nix-index that uses this variable. Is comma maybe wrapped with an old nix-index version that does use NIX_INDEX_DATABASE yet?

[Mic92]

Ah, but it's comma that prints the warning. It doesn't implement NIX_INDEX_DATABASE at all.

[Mic92]

Proper fix: nix-community/comma#73

[hraban]

I'm not sure I follow how a tool that doesn't touch the database would complain about its age but I believe you. 👍 :)