Using fish shell with git bash on windows

git-bash-fish.md

Using fish shell with git bash on windows

To install fish shell on windows the options are:

• Cygwin
• WSL
• MSYS2

Since git bash is based on MSYS2 it seems a good fit to install fish. The problem is that git bash is a lightweight version of MSYS2 which does not include pacman as a package management, used to install fish.

This OS thread has great suggestions on how to solve this problem including using the full MSYS2. But the best solution for me was this answer by Michael Chen which installs pacman on git bash.

I'll reproduce here his answer with some updates that made it work for me:

Step 1

Download pacman, pacman-mirrors and msys2-keyring from MSYS2's site. Also, for fish to work it is necessary download gcc-libs since uses msys-stdc++-6.dll.

The files are in the zst format. To decompress to tar format download the windows version of the zstd tool and execute these commands from cmd:

zstd.exe -d msys2-keyring-1_20210213-2-any.pkg.tar.zst
zstd.exe -d pacman-mirrors-20210423-2-any.pkg.tar.zst
zstd.exe -d pacman-6.0.0-2-x86_64.pkg.tar.zst
zstd.exe -d gcc-libs-10.2.0-1-x86_64.pkg.tar.zst

Step 2

From git bash root unpack the tar files and restore the packages. It can be necessary to open git bash as admin.

cd /
tar -xvf ~/Downloads/msys2-keyring-1_20210213-2-any.pkg.tar
tar -xvf ~/Downloads/pacman-mirrors-20210423-2-any.pkg.tar
tar -xvf ~/Downloads/pacman-6.0.0-2-x86_64.pkg.tar
tar -xvf ~/Downloads/gcc-libs-10.2.0-1-x86_64.pkg.tar
pacman-key --init
pacman-key --populate msys2
pacman -Syu

Step 3

To sync the metadata files it's needed to run the commands below. This step takes some minutes to finish.

URL=https://github.com/git-for-windows/git-sdk-64/raw/main
cat /etc/package-versions.txt | while read p v; do d=/var/lib/pacman/local/$p-$v;
 mkdir -p $d; for f in desc files install mtree; do curl -sSL "$URL$d/$f" -o $d/$f;
 done; done

Step 4

Now that pacman is installed on git bash, fish can be installed:

pacman -S fish

Step 5

If all is well and working fine edit the file ~/.bashrc adding these lines to make fish as the default shell:

if [ -t 1 ]; then
exec fish
fi

The instructions, as written, worked perfectly for me.

This worked with one additional step.

The command pacman -Syu (in Step 2 above) failed with an "incompatible database" error. Running pacman-db-upgrade -r /../ upgraded the database and then I could do the remaining steps. From comment: https://stackoverflow.com/questions/32712133/package-management-in-git-for-windows-git-bash/65204171#comment124229393_65204171

Also, I slightly changed Step 3 to show me what it's doing because it takes a while:

URL=https://github.com/git-for-windows/git-sdk-64/raw/main
cat /etc/package-versions.txt | while read p v; do
  d=/var/lib/pacman/local/$p-$v
  mkdir -p $d
  for f in desc files install mtree; do
    echo "$URL$d/$f" ..... $d/$f
    curl -sSL "$URL$d/$f" -o $d/$f
  done
done

Worked right out of the box as described above (Step 1-5).
Make my day, Sir!

I couldn't get this to work (I got error: keyring is not writable)

The only thing that worked was:

nano /etc/pacman.conf
edit
SigLevel = Required DatabaseOptional
change to
SigLevel = Optional TrustAll

rerun pacman -Sy fish

So far, git-bash and fish is the only combo where pipenv can activate an environment. (cygwin+fish and msys2+fish couldn't activate a venv)

When running pacman -Syu I get this:

Anyone else?

Something folks might try is making sure that your GitBash is running with administrator privileges. If you don't have admin privileges, your tar step will fail, and then commands won't be found, or things won't be writeable.

I've run all the instructions, exactly as written, on five different devices so far, including today, and it's worked perfectly every time.

Thank you for sharing this, it's helpful :D

It works but gives this prompt every time the fish shell initializes:

error: Unable to open shared memory with path '/fish_shmem_197609': Permission denied

But it doesn't do that when you run the Terminal app as administrator or you run the fish command in sudo mode

@voidptr @rafaelpadovezi

https://gist.github.com/crossgate10/a67421cfed9c6d11cdfb50e5eac14fc0?permalink_comment_id=4997234#gistcomment-4997234 this worked for me, I had to also start and exit fish one time in the root shell

It works for me, although I had an issue while installing, messages containing CreateThread failed for sig and child_copy: data read copy failed. I had to force close the Git Bash window.
I also have an issue like @eedrxs Unable to open shared memory with path '/fish_shmem_4096'

What is the step 3 for exactly? Is this needed after executing a 'pacman -Syu'

BTW, these two packages in the latest git-for-windows release's package-versions.txt are 404 in https://github.com/git-for-windows/git-sdk-64/raw/main:
mingw-w64-x86_64-libwinpthread-git 12.0.0.r329.g8f7b5ce36-1
msys2-runtime 3.5.4-1

Another solution for errors like...

error: Unable to open shared memory with path '/fish_shmem_1062462': Permission denied

...is to set write permission to everyone in the Windows filesystem for folder: C:\Program Files\Git\dev\shm
In this folder fish wants to create the file fish_shmem_1062462 (where 1062462 is your user id)

Thanks @phibel it works for me 👍