missing dejavusansmono in rrdtool pango cairo fontconfig

[macports at parvis.nl]

> On 2018-05-02, at 16:15, Rainer Müller <raimue at macports.org> wrote:
> 
> On 2018-05-02 12:44, macports at parvis.nl wrote:
>> (...)
>> Pango has a simple tool to show font examples:
>> pango-view --backend=<backend> --text '   iiiiwwww  ' --font 'DejaVuSansMono 36' # execute in XQuartz
> 
> I think this should be
> --font 'DejaVu Sans Mono 36'
> At least it only works for me with spaces when I manually install the font to /Library/Fonts/DejaVuSansMono.ttf.

It should work with and without spaces, even in lowercase:
fc-match dejavusansmono
DejaVuSansMono.ttf: "DejaVu Sans Mono" "Book"
fc-match 'dejavu sans mono'
DejaVuSansMono.ttf: "DejaVu Sans Mono" "Book"

>> (...)
>> I cannot oversee the consequences of disabling 'quartz' for cairo.
> 
> The native macOS font renderer searches for fonts only in paths such as ~/Library/Fonts, /Library/Fonts, and /System/Library/Fonts as documented in [1]. There does not seem to be a way to extend that.

Indeed, symlinks don't work, copy does.
If you manually install DejaVu from /opt/local/share/fonts, FontBook complains that it cannot validate, but FB is too picky here.
> 
> We could install our fonts to a path such as /Library/Fonts/MacPorts/ to make them available to native applications by default. However, this would be a long-term solution as that requires changes in base for a ${fonts_dir} to be handled just like ${applications_dir}.

That is probably the best solution, but indeed for the long term.

>> On the pango mailing list, Behdad Esfahbod offered the solution to set environment variable 'env var PANGOCAIRO_BACKEND=fc' and that works fine.
> 
> While I agree this is a problem that should be solved for all ports, one workaround for rrdtool would be to use a simple shell script wrapper that exports this environment variable before executing the real binary.

Can do, but there are other applications that use fonts from macports. Making a wrapper for all is also a lot of work, for a temporary solution.

> However, that is only necessary if rrdtool can only work correctly with "DejaVu Sans Mono". Would it be acceptable to use a different font that is always available for the time being? Even a generic 'monospace' should give similar results.

Munin, where I am currently working on, explicitly defines DejaVuSans and DejaVuSansMono. Both are substitued by Helvetica. That cannot be handled by a wrapper but requires patches, to Menlo for example.

> Rainer


I never would have thought that porting Munin was so complicated. I'd prefer to start with ddrescue and foremost, my heart lies at the OS and things like filesystems.

Paul.