thunderbird@78: enable smartcard gpg support

[chpio]

Describe the bug
The "new" thunderbird@78 has native support for gpg now.

To Reproduce
Steps to reproduce the behavior:

1. install thunderbird@78
2. configure the gpg key manually
3. the mail encryption doesn't work

Expected behavior
It should support gpg smartcards or at least have an option to install all needed dependencies (gpgme).

Notify maintainers
@eelco
@lovesegfault
@pierron
@vcunat

Metadata
Please run nix-shell -p nix-info --run "nix-info -m" and paste the result.

• system: "x86_64-linux"
• host os: Linux 5.8.10, NixOS, 21.03pre244045.1179840f9a8 (Okapi)
• multi-user?: yes
• sandbox: yes
• version: nix-env (Nix) 2.3.7
• channels(root): "nixos-21.03pre244045.1179840f9a8"
• channels(thomas): "nixpkgs-21.03pre243895.72b9660dc18"
• nixpkgs: /home/thomas/.nix-defexpr/channels/nixpkgs

[vcunat]

You need to download and install GnuPG yourself. In addition, you must ensure the GPGME C library is installed in a corresponding version. You must ensure that Thunderbird 78 can find GPGME in the system library search path.

If I get it right, you can test it without rebuilding anything by:

env LD_LIBRARY_PATH="$(nix-build -QA nixos.gpgme.out)/lib" PATH="$(nix-build -QA nixos.gnupg)/bin:$PATH" thunderbird

(you still need to do the other steps from the wiki post)

[pittma]

I'm up against this one as well and have downgraded to 68 for the time being. I'm seeing something like what's stated in this Thunderbird bug.

[vcunat]

That's not ideal, as 68 has unfixed vulnerabilities (though perhaps hard to exploit if you're careful with e-mail content).

[pittma]

That's not ideal, as 68 has unfixed vulnerabilities (though perhaps hard to exploit if you're careful with e-mail content).

Turns out I was premature on that anyway. 68 failed to build.

[pittma]

With a slight modification to @vcunat's command above, I was able to get the pinentry prompt to pop up:

 LD_LIBRARY_PATH="$(nix-env -q --out-path gpgme | awk '{print $2}')/lib" thunderbird

[nh2]

I put the equivalent of @vcunat's fix from #98765 (comment) into PR #107122.

Please test!

Configuration instructions with pictures e.g. on https://anweshadas.in/how-to-use-yubikey-or-any-gpg-smartcard-in-thunderbird-78/