can't compile F# projects on microsoft/dotnet:2.1-sdk-alpine (bash dependency)

Steps to reproduce

docker run --rm microsoft/dotnet:2.1-sdk-alpine /usr/share/dotnet/sdk/2.1.301/FSharp/RunFsc.sh

Expected behavior

The F# compiler runs on published SDK image. A couple of simple solutions are:

• install bash on the Alpine SDK image
• change the shell script to not be bash specific

docker run --rm microsoft/dotnet:2.1-sdk-alpine sh /usr/share/dotnet/sdk/2.1.301/FSharp/RunFsc.sh
/usr/share/dotnet/sdk/2.1.301/FSharp/RunFsc.sh: line 9: syntax error: bad substitution

Actual behavior

env: can't execute 'bash': No such file or directory

I can’t build any F# projects without installing bash first. Workaround:

docker run --rm microsoft/dotnet:2.1-sdk-alpine sh -c "apk update; apk add bash; /usr/share/dotnet/sdk/2.1.301/FSharp/RunFsc.sh"

Environment data

dotnet --info output:

cc @KevinRansom

[ghost]

that would need work in roslyn for csharp and vb

@livarcocc, can you point to those scripts in roslyn? I think it used to be through scripts, RunCsc and RunVb, but not anymore?

@svick, we don’t need to write in Almquist shell Alpine. If the scripts are written in Unix/Bourne Shell with shebang #!/usr/bin/env sh, that just works in all distros of BSD, Linux, Mac, Solaris.

---

That is one of the reasons why many utilities out there such as npm use Unix/Bourne shell instead of bash. In .NET repos, bashism is a normal trait probably because it saves 10-15 minutes of figuring-out and coding time from devs who are new to Unix shells. It is also really a very poor excuse to shove bash down the throats of all consumers, even those who made a choice to use other shells. So please, do consider spending some time and updating the scripts (at least those that are shipped with product and related to runtime) to the common denominator, Unix Shell.

- #!/usr/bin/env bash
+ #!/usr/bin/env sh

... and then some changes in the file ...
... it is hard at first, then gets easier ...
... everything that is possible in bash is possible in sh with bit of an effort ...

This is really a thing to invest time on when you have widespread library/product. There are people in .NET who are trying to reduce amount of dependencies, this could be categories under that epic.

Then there are scripts under github.com/dotnet, that are fully Unix Shell compatible, but yet having bash shebang on the top… This shows lack of interest/awareness.

At least effort could be started by avoiding bash in new scripts (in dotnet/arcade for example)…

re: https://github.com/Microsoft/omi/issues/497

cc @Petermarcu, @weshaggard

[ctaggart]

We want the 2.1-runtime-alpine as slim as possible. We don’t care if 2.1-sdk-alpine grows in size to accommodate a bash install. We do want the tools to work out of the box. Please add bash to the sdk until product removes it is a dependency.