Hi Guix, I recently tried re-entering an older environment via: $ guix describe Generation 128 Jul 06 2022 14:50:39 (current) guix 17892c5 repository URL: https://git.savannah.gnu.org/git/guix.git branch: master commit: 17892c5f9c5c5c93325884834a58cc2a4fafa51f sfl-packages 6385881 repository URL: https://gitlab.com/Apteryks/sfl-guix-channel branch: master commit: 6385881124429016f750b0f562b70e07f592275e $ guix time-machine -C channels.scm -- shell with in the current directory the project manifest file: --8<---------------cut here---------------start------------->8--- (packages->manifest (map specification->package (list ;; General utilities. "bash" "coreutils" "cpio" "cqfd" "findutils" "gawk" "git" "grep" "gzip" "info-reader" ;to generate the info dir entry "less" ;for a better git experience "make" "man-db" ;to generate the manpages database "pandoc" "pict" "sed" "openssh" ;for the SSH client used by git "tar" "tree" "wget" ;; Python and libraries. "python-matplotlib" "python-paramiko" "python-robotframework" "python-robotframework-datadriver" "python-robotframework-sshlibrary" "python-robotframework-stacktrace" "python-scp" "python-selenium" "python-tenacity" "python-wrapper" ;; Drivers "python-labjack" ;; Development tools. "python-flake8" "python-flake8-isort" "python-ipython" "python-ipython-documentation" ;; To use ipdb with Python's breakpoint(): ;; 'export PYTHONBREAKPOINT=ipdb.sset_trace' ;; then set 'breakpoint()' in Python sources or ;; 'Evaluate breakpoint()' in RobotFramework sources. "python-ipdb" "python-isort" "python-pdbpp" ;for the 'sticky' mode "python-pylint" "python-robotframework-lint" ;; Browsers. "icecat" "ungoogled-chromium"))) --8<---------------cut here---------------end--------------->8--- and the channels.scm file: --8<---------------cut here---------------start------------->8--- (list (channel (inherit %default-guix-channel) (commit "ceeb2bfcaeb4380e01d26c8425e28b94ac13558a"))) ;2022-06-07 --8<---------------cut here---------------end--------------->8--- and was surprised to be greeted with the following error: --8<---------------cut here---------------start------------->8--- (repl-version 0 1 1) (exception %exception (non-self-quoting 140737300283024 "#<&message message: \"unsupported manifest format\">")) /var/log/guix/drvs/j8/0wjfx7s7nxhcn0wjxfysnnv2knx0c1-guix-package-cache.drv (END) --8<---------------cut here---------------end--------------->8--- What does it mean? Which manifest is it referring to? Thanks, Maxim