Hi Guix, I have been playing with nested Guix containers recently, with some suprising findings, and I am wondering if what I am doing is considered officially supported or not.
First: why? My use case is scientific workflows, for example using snakemake. I want to run my workflows in Guix containers, for reproducibility plus other reasons. But my workflows run other programs in their tasks (basically just "shelling out"), and those tasks may use their own Guix containers. Superficially, this works fine if I add the "guix" package to my "outer" container and expose the store plus the daemon's socket: guix shell -C guix \ --expose=/var/guix/daemon-socket/socket \ --expose=/gnu/store \ -- \ guix shell -C coreutils -- ls / But now for the first surprise: $ guix describe Generation 35 janv. 19 2023 12:34:57 (current) guix 8221cb6 repository URL: https://git.savannah.gnu.org/git/guix.git branch: master commit: 8221cb6d2ae5624829bf514d25ae234c073e35d5 $ guix shell -C guix -- guix describe guix 9fe5b49 repository URL: https://git.savannah.gnu.org/git/guix.git branch: master commit: 9fe5b490df83ff32e2e0a604bf636eca48b9e240 The Guix in my container is an older one, apparently the 1.4.0 release. Why? Can I change this? My first attempt was time-machine: guix shell -C -N guix nss-certs \ --expose=/var/guix/daemon-socket/socket \ --expose=/gnu/store \ -- \ guix time-machine -C channels.scm -- describe Updating channel 'guix' from Git repository at 'https://git.savannah.gnu.org/git/guix.git'... Authenticating channel 'guix', commits 9edb3f6 to 8221cb6 (331 new commits)... Computing Guix derivation for 'x86_64-linux'... | guix 8221cb6 repository URL: https://git.savannah.gnu.org/git/guix.git branch: master commit: 8221cb6d2ae5624829bf514d25ae234c073e35d5 Great! Except that every time I run this command, it does the channel update from scratch, so it's prohibitively slow. Sharing ${HOME}/.cache/guix seems to fix that. So... finally... guix shell -C -N guix nss-certs \ --expose=/var/guix/daemon-socket/socket \ --expose=/gnu/store \ --share=${HOME}/.cache/guix \ -- \ guix time-machine -C channels.scm \ -- \ shell -C coreutils \ -- \ ls / guix shell: error: mount: mount "none" on "/tmp/guix-directory.vpOEDC/sys": Operation not permitted Now I am lost. It doesn't matter which command I put on the last line, it's creating a container via time-machine running in another container that leads to the error. Any ideas? Cheers, Konrad.