Some build on my local Cuirass instance (use-subsitute? enabled, no 
remote workers) seem to be stuck in the 'scheduled' state. I also have 
the following errors in /var/log/cuirass.log:

> 2022-07-29 14:58:21 2022-07-29T14:58:21 next evaluation in 900 seconds
> 2022-07-29 14:59:24 2022-07-29T14:59:24 error: substituter started: 
> '/gnu/store/m970q0ih2r21gxd3nl2rjvj992cy2f8d-attica-5.70.0'
> 2022-07-29 14:59:25 2022-07-29T14:59:25 error: substituter started: 
> '/gnu/store/ljiihw2lvhbjakga17f0jlrjarrhgwlq-lm-sensors-3.6.0-lib'
> 2022-07-29 15:00:02 2022-07-29T15:00:02 error: substituter started: 
> '/gnu/store/ncljl624qh7kd4ajpr7s535la7k6rhdh-gnuplot-5.4.3'
> 2022-07-29 15:00:02 2022-07-29T15:00:02 error: substituter started: 
> '/gnu/store/9c4cjdbmh07cq4jjw5vn957rhrdf9yrh-karchive-5.70.0'
> 2022-07-29 15:00:02 2022-07-29T15:00:02 error: substituter started: 
> '/gnu/store/wb76df1b64axlhpx5rwkzc1pz9308cyl-kcodecs-5.70.0'
> 2022-07-29 15:00:02 2022-07-29T15:00:02 error: substituter started: 
> '/gnu/store/1aflwlwb62mwa204fkyp8ip592fd08vr-kconfig-5.70.0'
> 2022-07-29 15:00:02 2022-07-29T15:00:02 error: substituter started: 
> '/gnu/store/02cn7bghsf0151bysq8if3kybfp04a38-kcoreaddons-5.70.0'
> 2022-07-29 15:00:02 2022-07-29T15:00:02 error: substituter started: 
> '/gnu/store/mfdlj4v7cd6c6fw73850jiz4h4yw4pj5-kguiaddons-5.70.0'
> 2022-07-29 15:00:02 2022-07-29T15:00:02 error: substituter started: 
> '/gnu/store/ws15kpxd0cs2a0lpsjpzz19c295lqsrn-ki18n-5.70.0'
> 2022-07-29 15:00:02 2022-07-29T15:00:02 error: substituter started: 
> '/gnu/store/f4mxrb2i8y6d4dn2gl744bxrr1rhvh41-kirigami-5.70.0'
> 2022-07-29 15:00:02 2022-07-29T15:00:02 error: substituter started: 
> '/gnu/store/pbbyhn7s05ngqdm4xdypn9f575jg975d-kitemviews-5.70.0'
> 2022-07-29 15:00:03 2022-07-29T15:00:03 error: substituter started: 
> '/gnu/store/v3vpav96lwzdyc7j0xaddwz2vyaf31n0-kwayland-5.70.0'
> 2022-07-29 15:00:03 2022-07-29T15:00:03 error: substituter started: 
> '/gnu/store/w05f3vnzjfqfcng0b8703iws19yrs6jj-kwidgetsaddons-5.70.0'
> 2022-07-29 15:00:03 2022-07-29T15:00:03 error: substituter started: 
> '/gnu/store/qg8fhg6zb26ywhsrvjkixywdkw0p2ssw-kwindowsystem-5.70.0'
and (maybe related?)

> 2022-07-29 14:55:40 2022-07-29T14:55:40 error: build started: 
> '/gnu/store/2y7yn33k9rb6475wmiv42fmj5q2dk7f5-rust-clircle-0.3.0.tar.gz.drv'
> 2022-07-29 14:55:41 2022-07-29T14:55:41 error: build succeeded: 
> '/gnu/store/2y7yn33k9rb6475wmiv42fmj5q2dk7f5-rust-clircle-0.3.0.tar.gz.drv'
> 2022-07-29 14:55:41 2022-07-29T14:55:41 error: build started: 
> '/gnu/store/sh33h0nkj46yskcjqadd4fbic7mzjif5-rust-codepage-0.1.1.tar.gz.drv'
> 2022-07-29 14:55:41 2022-07-29T14:55:41 error: build succeeded: 
> '/gnu/store/sh33h0nkj46yskcjqadd4fbic7mzjif5-rust-codepage-0.1.1.tar.gz.drv'
> 2022-07-29 14:55:41 2022-07-29T14:55:41 error: build started: 
> '/gnu/store/02zw16fzzkzyv4nl5jwh6gcslawl0bzb-rust-clircle-0.3.0.drv'
> 2022-07-29 14:55:43 2022-07-29T14:55:43 error: build succeeded: 
> '/gnu/store/3iq81ifwhmdxkbx7v831hr8yq10m89iw-rust-chunked-transfer-1.4.0.drv'
> 2022-07-29 14:55:43 2022-07-29T14:55:43 error: build started: 
> '/gnu/store/8v1hqz6245k54na6ha1a2vzy89jvnpqq-rust-codespan-reporting-0.11.0.tar.gz.drv'
> 2022-07-29 14:55:43 2022-07-29T14:55:43 error: build failed: 
> '/gnu/store/02zw16fzzkzyv4nl5jwh6gcslawl0bzb-rust-clircle-0.3.0.drv'
> 2022-07-29 14:55:43 2022-07-29T14:55:43 error: build started: 
> '/gnu/store/mssmpapyqa9pwlp7kjwf63q8984ln1fr-rust-color-quant-1.1.0.tar.gz.drv'
> 2022-07-29 14:55:44 2022-07-29T14:55:44 error: build succeeded: 
> '/gnu/store/8v1hqz6245k54na6ha1a2vzy89jvnpqq-rust-codespan-reporting-0.11.0.tar.gz.drv'
> 2022-07-29 14:55:44 2022-07-29T14:55:44 error: build started: 
> '/gnu/store/0mnl93k7lzzhan07any0i09h50rq4ivf-rust-colored-1.9.3.tar.gz.drv'
> 2022-07-29 14:55:44 2022-07-29T14:55:44 error: build succeeded: 
> '/gnu/store/mssmpapyqa9pwlp7kjwf63q8984ln1fr-rust-color-quant-1.1.0.tar.gz.drv'
> 2022-07-29 14:55:44 2022-07-29T14:55:44 error: build started: 
> '/gnu/store/35ryizhxy8x15fhyi621nslnhcjf86b3-rust-codespan-reporting-0.11.0.drv'
> 2022-07-29 14:55:44 2022-07-29T14:55:44 error: build succeeded: 
> '/gnu/store/0mnl93k7lzzhan07any0i09h50rq4ivf-rust-colored-1.9.3.tar.gz.drv'
I'd expect 'error: build failed' to happen sometimes, but not 'error: 
build started'.

Greetings,
Maxime.