Include ctags optional compiled features

[tartley]

Optional compiled features are reported by ctags --version.

Our current snap, 0.2019-12-16+17:58:20+e0a976d7, reports:

Universal Ctags 0.0.0(e0a976d7)...
Compiled: Dec 16 2019, 17:58:44
...
Optional compiled features: +wildcards, +regex, +iconv, +option-directory, +xpath, +json, +interactive, +yaml, +packcc

The 'apt' installed ctags reports:

Universal Ctags 0.0.0...
Compiled: Jan 6 2019, 23:23:29
...
Optional compiled features: +wildcards, +regex, +iconv, +option-directory, +xpath, +json, +interactive, +sandbox, +yaml

ie. the snap is missing "+sandbox"

and the snap has "+packcc" but the apt does not.

Maybe we should make the snap the same as the apt? Or maybe the apt makes bad choices and we should just include what we think is best? Before deciding, we ought to look up what the compile-time features actually do. eg. maybe +packcc was introduced since the apt release was compiled 11 months ago, so we could keep it enabled, on the assumption that future apt releases will include it.

[tartley]

see https://github.com/universal-ctags/ctags/blob/master/docs/autotools.rst

[tartley]

@Mandy91 I updated this issue to make it clear what I think ought to be done. Shout if you disagree.

[masatake]

+sandbox requires libseccomp.

[tartley]

Good to know, thank-you!