Hello, Felix's patch is from issue #69343, one is also squashed into [PATCH 2/7]. In [PATCH 2/7], does the mbegin above the mlet work, or is its value discarded? Guix deploy seems to work the same way. In [PATCH 7/7] I try to add a test for the guix deploy rollback behavior. See attachment, why does this error occur? Cheers, Herman Felix Lechner (1): Rename two remote variables confusingly named 'generations'. Herman Rimm (6): monads: Add 'mmatch'. gnu: machine: ssh: Refactor roll-back-managed-host. gnu: machine: ssh: Return monadic value from roll-back-managed-host. gnu: machine: Remove &deploy-error. gnu: machine: ssh: Roll-back on failure. WIP: gnu: tests: Add module for guix deploy tests. doc/guix.texi | 6 ++ gnu/machine.scm | 17 +--- gnu/machine/ssh.scm | 122 +++++++++++------------- gnu/tests/deploy.scm | 203 ++++++++++++++++++++++++++++++++++++++++ guix/monads.scm | 11 +++ guix/scripts/deploy.scm | 8 +- 6 files changed, 279 insertions(+), 88 deletions(-) create mode 100644 gnu/tests/deploy.scm base-commit: 11855e1c2863c56d9a3364cdac614a529a1c7cc2 -- 2.45.2