Re: [gentoo-user] pango, freetype, and harfbuzz: circular dependencies?

[Michael]

Hi Matt,

On Saturday, 17 July 2021 17:19:46 BST Matthias Hanft wrote:
> Hi,
>
> doing the weekly "emerge --sync" and "emerge -aDuv @world", portage
> suddenly asks me to set the "harfbuzz" USE flag for "freetype". The
> exact messages are
>
> --- cut here ---
>
> emerge: there are no ebuilds built with USE flags to satisfy
> ">=media-libs/freetype-2.5.0.1:2=[harfbuzz,png,abi_x86_32(-)?,abi_x86_64(-)?
> ,abi_x86_x32(-)?,abi_mips_n32(-)?,abi_mips_n64(-)?,abi_mips_o32(-)?,abi_s390
> _32(-)?,abi_s390_64(-)?]". !!! One of the following packages is required to
> complete your request: - media-libs/freetype-2.10.4::gentoo (Change USE:
> +harfbuzz)
> (dependency required by "x11-libs/pango-1.48.7::gentoo" [ebuild])
> (dependency required by "net-analyzer/rrdtool-1.7.2-r100::gentoo[graph]"
> [installed]) (dependency required by "net-mail/mailgraph-1.14-r2::gentoo"
> [installed]) (dependency required by "@selected" [set])
> (dependency required by "@world" [argument])
>
> --- cut here ---
>
> on my 32-bit Gentoo. On my 64-bit Gentoo, it looks pretty similar:
>
> --- cut here ---
>
> The following USE changes are necessary to proceed:
>  (see "package.use" in the portage(5) man page for more details)
> # required by x11-libs/pango-1.48.7::gentoo
> # required by net-analyzer/rrdtool-1.7.2-r100::gentoo[graph]
> # required by net-mail/mailgraph-1.14-r2::gentoo
> # required by @selected
> # required by @world (argument)
>
> >=media-libs/freetype-2.10.4 harfbuzz
>
> --- cut here ---
>
> Of course, I just could do that, but "equery u freetype" tells me for
> "harfbuzz": "WARNING: may trigger circular dependencies!"
>
> Some googling showed me that circular dependencies seem to be a very,
> very ugly thing which you can't easily get rid of.
>
> Just turning off all unneeded USE flags isn't easy either - for example,
> I'm using mailgraph for graphical display on my website, which needs
> rrdtool[graph], which needs pango, which needs freetype... and there
> are some more dependencies on *real* used packages.
>
> How should I proceed, avoiding circular dependencies?
>
> Thank you in advance,
>
> -Matt

I had to set USE="harfbuzz" for freetype and yes, you are right, there is a 
warning there:

 ~ $ equery u freetype
[ Legend : U - final flag setting for installation]
[        : I - package is installed with flag     ]
[ Colors : set, unset                             ]
 * Found these USE flags for media-libs/freetype-2.10.4:
 U I
 + + X                 : Add support for X11
 - - abi_x86_32        : 32-bit (x86) libraries
 + + adobe-cff         : Use Adobe CFF as default font-renderer 
 - - bindist           : Disable ClearType support (see http://freetype.org/
patents.html) 
 - - brotli            : Enable brotli decompression support via app-arch/
brotli
 + + bzip2             : Support bzip2 compressed PCF fonts. 
 + + cleartype_hinting : New bytecode hinting mode for TrueType fonts that 
activates subpixel hinting (a.k.a. ClearType hinting) by default
 - - debug             : Enable extra debug codepaths, like asserts and extra 
output. If you want to get meaningful backtraces see https://wiki.gentoo.org/
wiki/Project:Quality_Assurance/Backtraces
 - - doc               : Add extra documentation (API, Javadoc, etc). It is 
recommended to enable per package instead of globally
 - - fontforge         : Install internal headers required for TrueType 
debugger in media-gfx/fontforge (built with USE=truetype-debugger)
 + + harfbuzz          : Use media-libs/harfbuzz for auto-hinting OpenType 
fonts. WARNING: may trigger circular dependencies!
 + + png               : Add support for libpng (PNG images)
 - - static-libs       : Build static versions of dynamic libraries as well
 - - utils             : Install utilities and examples from ft2demos 

I have not come across any problems on amd64 arch, but have not tried it on a 
32bit system to know if it will cause any problems.