The libgd-dev package is missing some sort of relationship with the
libheif-dev package because the gdlib.pc file references the libheif.pc
file in Requires.private. Most uses of gdlib.pc aren't for static
linking in Debian so probably Recommends or Suggests is enough.

This bug report brought to you by adequate:

https://bonedaddy.net/pabs3/log/2013/02/23/inadequate-software/

$ adequate libgd-dev
libgd-dev:amd64: missing-pkgconfig-dependency gdlib => libheif

$ dpkg -L libgd-dev | grep -F .pc
/usr/lib/x86_64-linux-gnu/pkgconfig/gdlib.pc

$ grep libheif /usr/lib/x86_64-linux-gnu/pkgconfig/gdlib.pc
Requires.private:   zlib  libpng  freetype2 >= 9.8.3  fontconfig  libjpeg  xpm  libtiff-4  libwebp >= 0.2.0  libheif >= 1.7.0  libavif >= 0.8.2

$ apt-file search libheif.pc
libheif-dev: /usr/lib/x86_64-linux-gnu/pkgconfig/libheif.pc

$ apt-cache show libgd-dev | grep libheif-dev

$ COLUMNS=80 man adequate | grep -A5 pkgconfig
       missing-pkgconfig-dependency
           Dependency of a pkg-config (.pc) file shipped by this package
           couldn't be satisfied.

           References: Debian Policy §8.4.

We believe that the bug you reported is fixed in the latest version of
libgd2, which is due to be installed in the Debian FTP archive.

A summary of the changes between this version and the previous one is
attached.

Thank you for reporting the bug, which will now be closed.  If you
have further comments please address them to 1014500@bugs.debian.org,
and the maintainer will reopen the bug report if appropriate.

Debian distribution maintenance software
pp.
Ondřej Surý <ondrej@debian.org> (supplier of updated libgd2 package)

(This message was generated automatically at their request; if you
believe that there is a problem with it please contact the archive
administrators by mailing ftpmaster@ftp-master.debian.org)
Format: 1.8
Date: Thu, 07 Jul 2022 06:02:21 +0200
Source: libgd2
Architecture: source
Version: 2.3.3-3
Distribution: unstable
Urgency: medium
Maintainer: GD Team <team+gd@tracker.debian.org>
Changed-By: Ondřej Surý <ondrej@debian.org>
Closes: 1014500
Changes:
 libgd2 (2.3.3-3) unstable; urgency=medium
 .
   * Add missing libheif-dev and libavif-dev to libgd-dev depends
     (Closes: #1014500)
Checksums-Sha1:
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 0045892c6ca15bf6ec339795a6ebb509b1e3711f 31108 libgd2_2.3.3-3.debian.tar.xz
 d0746f3fef7d8f5f76596235aff8bcfed4d8e80e 9285 libgd2_2.3.3-3_amd64.buildinfo
Checksums-Sha256:
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Files:
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