# git hard-codes use of /bin/sh for aliases 3 messages from 2026-05-11 to 2026-05-11. Participants: Thorsten Glaser, brian m. carlson. Thread: https://gitlist.dev/t/65616 ## Thorsten Glaser, 2026-05-11 21:13 Subject: git hard-codes use of /bin/sh for aliases Message-ID: <6791cb26-16af-dcda-1dae-82b85da6fb0f@b1-systems.de> ``` Hi, git aliases don’t use the user’s shell but a hardcoded /bin/sh, and this cannot be made configurable. This, unfortunately, breaks quite some aliases and they cannot be made portable by adding something like core.sh = /bin/mksh to the .gitconfig. I’d love if this could be made configurable. bye, //Thorsten -- Thorsten Glaser Linux / Unix Developer Tel.: +49 160 91168501 E-Mail: tglaser@b1-systems.de B1 Systems GmbH Osterfeldstraße 7 / 85088 Vohburg / https://www.b1-systems.de/ GF: Ralph Dehner / Unternehmenssitz: Vohburg / AG: Ingolstadt, HRB 3537 ``` ## brian m. carlson, 2026-05-11 22:38 Subject: Re: git hard-codes use of /bin/sh for aliases Message-ID: In-Reply-To: <6791cb26-16af-dcda-1dae-82b85da6fb0f@b1-systems.de> ``` On 2026-05-11 at 21:13:18, Thorsten Glaser wrote: > Hi, > > git aliases don’t use the user’s shell but a hardcoded /bin/sh, > and this cannot be made configurable. > > This, unfortunately, breaks quite some aliases and they cannot > be made portable by adding something like core.sh = /bin/mksh > to the .gitconfig. > > I’d love if this could be made configurable. Yes, I believe they use `/bin/sh`, except on Windows, where they may look up things in the PATH. It is very much intentional that they use sh because it means that aliases work in a consistent way across platforms and that they work at all. On Linux, I have mksh, but my work machine on macOS does not, so specifying `core.sh = /bin/mksh` would not work on all my systems. If you have system-level aliases as well as user-level aliases, then you need to pick a particular shell and letting the user choose will likely break the system-level aliases. This is not a hypothetical: my last company shipped system-level aliases on development VMs while users were free to customize their user-level aliases (and shell). This will absolutely be a problem on Windows, where you have CMD, multiple versions of PowerShell, and bash, all with different syntax. Some versions of PowerShell also corrupt non-Unicode data sent through pipelines as well, which means they're effectively useless for general-purpose scripting. It can also lead to odd behaviour on some shells because, for instance, zsh runs a config file with `-c`, `.zshenv`, that can make the shell very much less POSIX compliant, so behaviour can differ substantially from sh. I'll also note that Git doesn't handle aliases specially. Git has a with-shell and a without-shell mode for running commands, and we use the former for aliases. We definitely do not want the with-shell mode to generically allow arbitrary shells because we cannot handle non-POSIX shells and will not quote correctly for them (almost certainly leading to security vulnerabilities). We also format the shell command as "%s \"$@\"", which also basically requires a POSIX shell to work, and we don't want to work around people's use of non-POSIX shells; that way madness lies. However, because mksh is POSIXy, you could build Git on your system with `SHELL_PATH=/bin/mksh`, which would use `/bin/mksh` everywhere that the shell is invoked. That feature exists primarily for systems where `sh` is not POSIXy or doesn't support `local` (which I know mksh does), but there's no reason you can't use it yourself. There has been some discussion about this issue in the past (in the context of PowerShell) at https://lore.kernel.org/git/CAAXzdLXt4+-34+OhS=Jn=-VeORN3Y2jMzzg9+bhyn88aN4hm0A@mail.gmail.com/ . -- brian m. carlson (they/them) Toronto, Ontario, CA ``` ## Thorsten Glaser, 2026-05-11 22:46 Subject: Re: git hard-codes use of /bin/sh for aliases Message-ID: <9f279637-c0fe-c88b-24de-3a00b957ae3b@b1-systems.de> In-Reply-To: ``` On Mon, 11 May 2026, brian m. carlson wrote: >On Linux, I have mksh, but my work machine on macOS does not, so >specifying `core.sh = /bin/mksh` would not work on all my systems. If But it could be made possible by pointing it to ~/.etc/bin/mksh on the Macintosh… >I'll also note that Git doesn't handle aliases specially. Git has a >with-shell and a without-shell mode for running commands, and we use the >former for aliases. Ah, okay. I was merely wondering that it was not configurable for aliases. When looking at the aliases in detail, I found that I already invoked mksh -c '…' in those that used mksh-specific code, and that the one that failed merely uses a recent POSIX sh construct that /bin/sh on a customer system does not yet implement and I could reword it. bye, //Thorsten -- Thorsten Glaser Linux / Unix Developer Tel.: +49 160 91168501 E-Mail: tglaser@b1-systems.de B1 Systems GmbH Osterfeldstraße 7 / 85088 Vohburg / https://www.b1-systems.de/ GF: Ralph Dehner / Unternehmenssitz: Vohburg / AG: Ingolstadt, HRB 3537 ```