database-migrator | export grafana.db to MySQL-compatible SQL file | SQL Database library

Check if this is similar to containers/buildah issue 475 :

I think it is because the system does not know how to execute the file.
FYI: What's the appropriate Go shebang line?

Also be aware of the difference between the shell form and exec form of CMD/ENTRYPOINT in Dockerfile.

just adding #!/bin/bash to my entry point file fixed the issue.

Or:

Turns out the #!/bin/bash was in my entry point file, but since I did a copy and paste into that file, the first line was a newline, not the #!/bin/bash, effectively ignoring it.
If this helps anyone as well: Deleted the empty line and all worked fine.

Or:

In case anyone finds this useful, you can get this issue if your shell script uses CRLF for line endings and/or UTF-8 with BOM (e.g. if you created a shell script file in Visual Studio).
Changing to LF only and straight UTF-8 fixed it for me.

Or (probably not your case, but to be complete):

For anyone who got a standard_init_linux.go:190: exec user process caused "no such file or directory" error after applying this fix, you're probably on an alpine base image which does not come with bash.

Replacing #!/bin/bash with #!/bin/sh will do the trick!