RFR: 7902970: Script build.sh will fail if the default shell is dash

[Jonathan Gibbons]

On Sat, 12 Jun 2021 15:05:49 GMT, Guoxiong Li <gli at openjdk.org> wrote:

> Hi all,
> 
> My local default shell is `dash`.
> 
> 
> $ ls -al /bin/*sh*
> -rwxr-xr-x 1 root root 1113504 Jun 7 2019 /bin/bash
> -rwxr-xr-x 1 root root 121432 Jan 25 2018 /bin/dash
> lrwxrwxrwx 1 root root 4 Sep 26 2020 /bin/rbash -> bash
> lrwxrwxrwx 1 root root 4 Sep 26 2020 /bin/sh -> dash
> lrwxrwxrwx 1 root root 4 Sep 26 2020 /bin/sh.distrib -> dash
> lrwxrwxrwx 1 root root 7 Sep 18 2020 /bin/static-sh -> busybox
> 
> 
> When I use the command `sh make/build.sh --help`, the build.sh will fail.
> Because the `dash` doesn't support the variables such as `BASH_SOURCE`.
> 
> 
> $ sh make/build.sh --help
> make/build.sh: 252: make/build.sh: Bad substitution
> make/build.sh: 253: make/build.sh: Bad substitution
> make/build.sh: 254: .: Can't open /build-support/build-common.sh
> 
> 
> The successful command is `bash make/build.sh --help`, which uses `bash` explicitly
> instead of the default shell `sh` implicitly.
> 
> This patch clarifies this situation in the README.
> Thanks for taking the time to review.
> 
> Best Regards,
> -- Guoxiong

Changes requested by jjg (Lead).

README.md line 33:

> 31: 
> 32:     % bash make/build.sh --jdk JDK-directory
> 33: 

Suggest simplifying it to:


If your shell is not compatible with `bash`, you may need to invoke `bash` explicitly:

     % bash make/build.sh --jdk JDK-directory

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PR: https://git.openjdk.java.net/jtreg/pull/12