vala, vala-devel: doesn't install valadoc unless +docs variant is used

[ryandesign (Ryan Carsten Schmidt)]

The vala and vala-devel ports don't install the valadoc program unless the +docs variant is selected. This is unexpected. We expect the +docs variant to install documentation related to the program. But valadoc is a program that other ports need to build themselves—folks does, for example.

The problem was introduced in [1dd4a0915ae3f58d2cd47fba00a9f34c9d612d8c/macports-ports].

Please change the vala and vala-devel ports so that the valadoc program is always installed again. Documentation that is large or time consuming to build should remain in the +docs variant, although I'm not sure that there is any.

[Christopher Nielsen <mascguy@…>]

In 7352fd2fee713ea5d9b89024a9df92af326d3640/macports-ports (master):

vala{,-devel}: add variant valadoc, enabled by default

• Replaces variant docs; new name is more accurate

See: #68895
Fixes: #70417

[neverpanic (Clemens Lang)]

In 2870311521cf94f9955aa876710af9ba781aecba/macports-ports (master):

vala{,-devel}: add missing lib dep for graphviz

`
:) cllang@gallumbits:~$ sudo port -vy rev-upgrade
---> Scanning binaries for linking errors
Could not open /opt/local/lib/libcdt.5.dylib: Error opening or reading file (referenced from /opt/local/bin/valadoc-0.56)
Could not open /opt/local/lib/libcgraph.6.dylib: Error opening or reading file (referenced from /opt/local/bin/valadoc-0.56)
Could not open /opt/local/lib/libgvc.6.dylib: Error opening or reading file (referenced from /opt/local/bin/valadoc-0.56)
---> Found 6 broken files, matching files to ports
---> Found 1 broken port, determining rebuild order
You can always run 'port rev-upgrade' again to fix errors.
The following ports will be rebuilt: vala @0.56.17+valadoc
`

This has probably been broken for a while, but
7352fd2fee713ea5d9b89024a9df92af326d3640 made valadoc a default variant.

See: #68895
See: #70417

[ryandesign (Ryan Carsten Schmidt)]

Unfortunately this introduces a dependency cycle; see #70546.

Why is a variant needed at all? By providing this variant, you provide an opportunity for ports to fail to build due to valadoc being missing.