Error building the server: \r\n line endings and bad interpreter

[Phundrak]

As reported in this PR which will hopefully bring this fork to Spacemacs, I noticed while building the server the following errors:

• Emacs reports

  /home/phundrak/.emacs.d/elpa/28.0/develop/pdf-tools-20210411.1603/build/server/autobuild -i /home/phundrak/.emacs.d/elpa/28.0/develop/pdf-tools-20210411.1603/
  /usr/bin/sh: /home/phundrak/.emacs.d/elpa/28.0/develop/pdf-tools-20210411.1603/build/server/autobuild: /bin/sh^M: bad interpreter: No such file or directory
  

• While running directly autobuild from the shell gives the following error:

  Failed to execute process './autobuild'. Reason:
  The file uses windows line endings (\r\n). Run dos2unix or similar to fix it.
  

I see two issues here:

1. The incorrect line endings
2. The use of /bin/sh.

Regarding the second issue, I think it would be safer to directly refer the shell to bash and not sh, since the latter can be symlinked to various shells depending on the OS, and not necessarily POSIX-compliant ones. bash on the other hand is present on most UNIX and POSIX systems, including macOS.

I will try to submit a PR soon to fix at least the first issue.

[lebensterben]

• You should never use bash. Some system have dash instead of bash.
• You should never use /bin/sh and always /usr/bin/env sh. /bin is never the standard path according to Linux Filesystem Specification.

[Phundrak]

Alright, so here’s the weird thing, when I clone locally the repo through git, `autobuild` actually has LF line endings, not CRLF. Running `dos2unix` does nothing, and Emacs indicates LF line endings too, so nothing I can modify. But, if I let Emacs (Spacemacs) download the package itself, I get a file with CRLF line endings. Maybe this is an issue from Spacemacs’ package manager?

* You should never use bash. Some system have dash instead of bash.

Fair enough, I did not know about dash.

* You should never use /bin/sh and always /usr/bin/env sh. /bin is never the standard path according to Linux Filesystem Specification.

Also true, this at least should be changed.

[vedang]

I don't think the line-ending problem is a pdf-tools problem. I'd appreciate it if users of spacemacs could investigate this on their end.

Re: changing the shebang line, I will create a separate issue to track this, I see it as a low hanging fruit and would love to accept a PR for it.

[vedang]

I've confirmed that all files in pdf-tools have the correct line endings, and have created an issue to track the #! change. Closing this ticket.