bug#67988: [Cuirass] ‘request-work’ responses received by several workers

[Ludovic Courtès]

Hello,

I’m under the impression that sometimes, when the server replies to
‘worker-request-work’ messages, its reply is received by more than just
the target worker, leading to builds being performed twice:

--8<---------------cut here---------------start------------->8---
ludo@berlin ~$ sudo grep lyhz5d1jb396m32dy0fs9h8vqzw95ddp 
/var/log/cuirass-remote-server.log
2023-12-23 00:15:29 141.80.167.184 (0LFowqzr): build started: 
'/gnu/store/lyhz5d1jb396m32dy0fs9h8vqzw95ddp-cdrdao-1.2.5.drv'.
2023-12-23 00:18:41 fetching 1 outputs of 
'/gnu/store/lyhz5d1jb396m32dy0fs9h8vqzw95ddp-cdrdao-1.2.5.drv' from 
http://141.80.167.184:5558
2023-12-23 00:18:45 build succeeded: 
'/gnu/store/lyhz5d1jb396m32dy0fs9h8vqzw95ddp-cdrdao-1.2.5.drv'
2023-12-23 00:21:20 141.80.167.159 (oNzYXCv5): build started: 
'/gnu/store/lyhz5d1jb396m32dy0fs9h8vqzw95ddp-cdrdao-1.2.5.drv'.
2023-12-23 00:24:31 fetching 1 outputs of 
'/gnu/store/lyhz5d1jb396m32dy0fs9h8vqzw95ddp-cdrdao-1.2.5.drv' from 
http://141.80.167.159:5558
2023-12-23 00:24:32 build succeeded: 
'/gnu/store/lyhz5d1jb396m32dy0fs9h8vqzw95ddp-cdrdao-1.2.5.drv'
ludo@berlin ~$ sudo ssh root@141.80.167.184 grep 
lyhz5d1jb396m32dy0fs9h8vqzw95ddp /var/log/cuirass-remote-worker.log
2023-12-23 00:12:32 0LFowqzr: building derivation 
`/gnu/store/lyhz5d1jb396m32dy0fs9h8vqzw95ddp-cdrdao-1.2.5.drv' (system: 
x86_64-linux)
2023-12-23 00:12:54 0LFowqzr: derivation 
/gnu/store/lyhz5d1jb396m32dy0fs9h8vqzw95ddp-cdrdao-1.2.5.drv build succeeded.
ludo@berlin ~$ sudo ssh root@141.80.167.159 grep 
lyhz5d1jb396m32dy0fs9h8vqzw95ddp /var/log/cuirass-remote-worker.log
2023-12-23 00:17:51 oNzYXCv5: building derivation 
`/gnu/store/lyhz5d1jb396m32dy0fs9h8vqzw95ddp-cdrdao-1.2.5.drv' (system: 
x86_64-linux)
2023-12-23 00:18:17 oNzYXCv5: derivation 
/gnu/store/lyhz5d1jb396m32dy0fs9h8vqzw95ddp-cdrdao-1.2.5.drv build succeeded.
--8<---------------cut here---------------end--------------->8---

This is with Cuirass 1.2.0-1.bdc1f9f.

To be continued…

Ludo’.