Hi Meiyo, thanks for the report. > I am using GuixSD 0.14. After upgrading fish shell to latest version(v2.7.1) and > running `guix gc`, fish shell does not work well. […] > Fish shell is installed in: > #+BEGIN_EXAMPLE > /gnu/store/ajbbi9cgj9j0my7v5habp0lcysaf2a51-fish-2.7.1/ > #+END_EXAMPLE > > But the environment variable $fish_function_path does not exist. And these > environment variables point to non-existent paths: > #+BEGIN_EXAMPLE > __fish_bin_dir /gnu/store/4jkxcz8kpy621ycmqn3rvs0fv6c98h6p-fish-2.7.1/bin > __fish_datadir /gnu/store/4jkxcz8kpy621ycmqn3rvs0fv6c98h6p-fish-2.7.1/share/fish > #+END_EXAMPLE Where are these environment variables defined? > In conclusion, I think some path related variables are not set > correctly when fish is compiled from source code and that caused the > bug I met. Some other packages record exact store references in cache files in the user’s home directory. As packages get upgraded and removed after garbage collection, these references become invalid. The question is whether these old store references are kept in files outside of the store (and thus are not directly under our control), or if the packages that Guix builds include incorrect references. I guess that it’s the former. As is the case for these other programmes that record paths in cache files, we would need to patch fish to record only the stable names of links to those files (e.g. ~/.guix-profile/foo/bar) rather than the actual file names in the store, which may disappear upon “guix gc”. -- Ricardo GPG: BCA6 89B6 3655 3801 C3C6 2150 197A 5888 235F ACAC https://elephly.net