cache action fails to unpack files in macOS CI

[thpani]

There's some issue with the cache action in build CI on macOS (not on Ubuntu).
It fails to unpack the received cache contents:

Example run: https://github.com/informalsystems/apalache/actions/runs/5290491810/jobs/9574713460

2023-06-15T08:49:11.1466950Z ##[group]Run john-shaffer/cache@59429c0461095f341a8cf7388e5d3aef37b95edd
2023-06-15T08:49:11.1467730Z with:
2023-06-15T08:49:11.1468220Z   path: /nix/store
/nix/var/nix/profiles

2023-06-15T08:49:11.1468580Z   key: macOS-nix-7903d8cd7ec0ca563357519261c9208a90c2e18e4a06a3aa51584d800c42edcc
2023-06-15T08:49:11.1469650Z   restore-keys: macOS-nix-
macOS-

2023-06-15T08:49:11.1470160Z ##[endgroup]
2023-06-15T08:49:11.3153330Z ##[warning]The `save-state` command is deprecated and will be disabled soon. Please upgrade to using Environment Files. For more information see: https://github.blog/changelog/2022-10-11-github-actions-deprecating-save-state-and-set-output-commands/
2023-06-15T08:49:12.8947660Z Received 0 of 1365208204 (0.0%), 0.0 MBs/sec
2023-06-15T08:49:13.8979370Z Received 79691776 of 1365208204 (5.8%), 37.9 MBs/sec
2023-06-15T08:49:14.9013480Z Received 142606336 of 1365208204 (10.4%), 45.2 MBs/sec
2023-06-15T08:49:15.9018780Z Received 213909504 of 1365208204 (15.7%), 50.9 MBs/sec
2023-06-15T08:49:16.9027140Z Received 289406976 of 1365208204 (21.2%), 55.1 MBs/sec
2023-06-15T08:49:17.9025780Z Received 360710144 of 1365208204 (26.4%), 57.2 MBs/sec
2023-06-15T08:49:18.9053450Z Received 436207616 of 1365208204 (32.0%), 59.3 MBs/sec
2023-06-15T08:49:19.9075990Z Received 507510784 of 1365208204 (37.2%), 60.4 MBs/sec
2023-06-15T08:49:20.9087540Z Received 578813952 of 1365208204 (42.4%), 61.2 MBs/sec
2023-06-15T08:49:21.9098730Z Received 645922816 of 1365208204 (47.3%), 61.5 MBs/sec
2023-06-15T08:49:22.9105480Z Received 704643072 of 1365208204 (51.6%), 61.0 MBs/sec
2023-06-15T08:49:23.9118550Z Received 767557632 of 1365208204 (56.2%), 60.9 MBs/sec
2023-06-15T08:49:24.9126170Z Received 826277888 of 1365208204 (60.5%), 60.5 MBs/sec
2023-06-15T08:49:25.9144120Z Received 884998144 of 1365208204 (64.8%), 60.2 MBs/sec
2023-06-15T08:49:26.9165880Z Received 947912704 of 1365208204 (69.4%), 60.2 MBs/sec
2023-06-15T08:49:27.9202340Z Received 1002438656 of 1365208204 (73.4%), 59.7 MBs/sec
2023-06-15T08:49:28.9224620Z Received 1065353216 of 1365208204 (78.0%), 59.7 MBs/sec
2023-06-15T08:49:29.9236220Z Received 1115684864 of 1365208204 (81.7%), 59.0 MBs/sec
2023-06-15T08:49:30.9252160Z Received 1182793728 of 1365208204 (86.6%), 59.3 MBs/sec
2023-06-15T08:49:31.9264990Z Received 1241513984 of 1365208204 (90.9%), 59.1 MBs/sec
2023-06-15T08:49:32.9263030Z Received 1300234240 of 1365208204 (95.2%), 59.0 MBs/sec
2023-06-15T08:49:33.9269240Z Received 1356819596 of 1365208204 (99.4%), 58.7 MBs/sec
2023-06-15T08:49:36.5299330Z Received 1365208204 of 1365208204 (100.0%), 52.8 MBs/sec
2023-06-15T08:49:36.5417150Z Cache Size: ~1302 MB (1365208204 B)
2023-06-15T08:49:36.5529200Z [command]/usr/bin/sudo /usr/local/bin/gtar -z -xf /Users/runner/work/_temp/984a3de9-c735-470f-8e2d-59a7c4a91806/cache.tgz -P -C /Users/runner/work/apalache/apalache --delay-directory-restore
2023-06-15T08:49:36.6446210Z /usr/local/bin/gtar: ../../../../../nix: Cannot mkdir: Read-only file system
2023-06-15T08:49:36.6450390Z /usr/local/bin/gtar: ../../../../../nix/store: Cannot mkdir: No such file or directory
2023-06-15T08:49:36.6453580Z /usr/local/bin/gtar: ../../../../../nix: Cannot mkdir: Read-only file system
2023-06-15T08:49:36.6455660Z /usr/local/bin/gtar: ../../../../../nix/store/2v5nj277h7lfyd5yhrbvz8wi2im07ckk-boehm-gc-8.2.2: Cannot mkdir: No such file or directory
2023-06-15T08:49:36.6456760Z /usr/local/bin/gtar: ../../../../../nix: Cannot mkdir: Read-only file system
2023-06-15T08:49:36.6457790Z /usr/local/bin/gtar: ../../../../../nix/store/2v5nj277h7lfyd5yhrbvz8wi2im07ckk-boehm-gc-8.2.2/lib: Cannot mkdir: No such file or directory
2023-06-15T08:49:36.6459240Z /usr/local/bin/gtar: ../../../../../nix: Cannot mkdir: Read-only file system
...

[thpani]

Unassigning myself, as there's no obvious fix for now

[shonfeder]

Is this happening with our current CI config, or was this an issue with the attempt to remove our caching workaround?

[thpani]

It's happening with the current config, that's why I tried to remove the workaround.

afaict, it's not breaking anything, just creating a lot of terminal noise.

OTOH, that workaround is also printing deprecation notices, so we should find a different solution at some point.