fish shell 4.6 adds systemd environment variable support, better emoji handling, and more

fish 4.6 introduces notable enhancements, starting with support for the SHELL_PROMPT_PREFIX, SHELL_PROMPT_SUFFIX, and SHELL_WELCOME environment variables. These options enable users to automatically prepend and append custom text to the left prompt, as well as display a tailored welcome message after the initial greeting, integrating easily with tools like systemd’s run0.

Building on display improvements, the default emoji width is now set to 2. This change improves compatibility for remote session users who connect from modern desktops to older systems. Following these changes, the tab completion pager has been updated to left-justify the description in each column, which increases the readability of completions.

In addition, set_color now allows finer control by enabling or disabling italics, reverse, strike-through, and underline individually, and adds --foreground and --reset options. Additionally, a startup error specific to macOS, triggered by slow terminal responses, has also been addressed.

Other updates include support for Spanish and Japanese translations, prevention of interruptions from resize signals like SIGWINCH during built-in output, recognition of Bash-style |& for combined piping of standard output and error streams, and improved fish_indent behavior which now preserves comments and newlines before brace blocks. A crash related to suspending certain pipelines with ctrl-z has been fixed as well.