Subject: bug#39725: closed (Re: bug#39725: /gnu/store/.links: base16 or base32?)

From: [email-masked] (GNU bug Tracking System)
Date: Sat, 22 Feb 2020 00:01:01 +0000

Your bug report

#39725: /gnu/store/.links: base16 or base32?

which was filed against the guix package, has been closed.

The explanation is attached below, along with your original report.
If you require more details, please reply to [email-masked].

-- 
39725: http://debbugs.gnu.org/cgi/bugreport.cgi?bug=39725
GNU Bug Tracking System
Contact [email-masked] with problems

Subject: Re: bug#39725: /gnu/store/.links: base16 or base32?
From: Ludovic Courtès <[email-masked]>
To: [email-masked]
Date: Sat, 22 Feb 2020 01:00:23 +0100
List-Id: <debbugs-submit.debbugs.gnu.org>

Ludovic Courtès <[email-masked]> skribis:

> (guix store deduplication) uses base16, but optimize-store.cc does:
>
>     /* Check if this is a known hash. */
>     Path linkPath = linksDir + "/" + printHash32(hash);
>
> … where ‘printHash32’ returns a nix-base32 string.  Oops!

Fixed in 4cb63a564d413c745983a608790a943ac07f8d67.

Subject: /gnu/store/.links: base16 or base32?
From: Ludovic Courtès <[email-masked]>
To: [email-masked]
Date: Fri, 21 Feb 2020 22:51:28 +0100
List-Id: <debbugs-submit.debbugs.gnu.org>

Seen while stracing guix-daemon during GC (the “deleting unused links”
phase):

--8<---------------cut here---------------start------------->8---
unlink("/gnu/store/.links/3a16c555c7c60f9c781895eec65a31a04a6cc535fff5a381499c1a4717d8f19f") = 0
unlink("/gnu/store/.links/1mm1n1xmjb1in2sv71kpa90n5iv30h24blzfj4z0icdssbly19kh") = 0
unlink("/gnu/store/.links/4213e7fe3db934f2817fbd0fb3a74e5395736fcc7633d295c557462cae88f945") = 0
unlink("/gnu/store/.links/1g46q6yf868x7wfqnzcy4rb8r780bqi986vjvb1n7xm4ln3jizzf") = 0
unlink("/gnu/store/.links/8b261f0461a89419ee4436d11ac828fc63a4d8d6473696262d020c17758964eb") = 0
unlink("/gnu/store/.links/0znm2gdxraz3i88r3iy838d86s1zfidx8gga4kwiqcsnmaz206d6") = 0
unlink("/gnu/store/.links/f3fe1645f86a6a1effd8e4f0dfcdaef8d73c8163c96d2b2cb42e0bd7c05d9b5b") = 0
unlink("/gnu/store/.links/69a86d84c31d5b728f6d7496413bac8a0bc06c388255f0b81868066463cff80f") = 0
unlink("/gnu/store/.links/0s0bb4pkm282srrdm61fd0lf9zn7r85s370llbp616pk4j2szkhs") = 0
unlink("/gnu/store/.links/a2b0c70e4c03f3247250155d4a2cfdf6a21e03458f892f4c2a9ba861259022f6") = 0
unlink("/gnu/store/.links/5faebd1dc60adbf32b430090a29248b86c56eba4805aeedc8d99c459a28b34eb") = 0
unlink("/gnu/store/.links/8d7d77f86a32f2a0a36b508dcbdc4a44c61dec284b9dc6299a8b7d18db9938dc") = 0
unlink("/gnu/store/.links/1cjlcwkyr59apcym97zaw8r2m4ahqc11zrm51aqzvwg3b0xvchhw") = 0
unlink("/gnu/store/.links/0z9cw4h1p4cm6jp4zap9db1lh60i0ynal0dxd2f8ilzp085wb1xj") = 0
unlink("/gnu/store/.links/1vzgxm1png21gf13v5ac3494h9zshy6y35cxk38pf6dd0qimcand") = 0
unlink("/gnu/store/.links/1r8xm4j57m9h99rvv80q2wgv29p3q42ws4s2f0c3jd9a77hl2qn8") = 0
--8<---------------cut here---------------end--------------->8---

There’s an inconsistency here!

(guix store deduplication) uses base16, but optimize-store.cc does:

    /* Check if this is a known hash. */
    Path linkPath = linksDir + "/" + printHash32(hash);

… where ‘printHash32’ returns a nix-base32 string.  Oops!

The effect is just that deduplication wouldn’t work as well as it could:
results from offloaded builds would be deduplicated among them but not
against other store items.

Ludo’.