Bug#1146881: cimg-dev: Does it need to depend on opencv?

[Ingo Saitz]

Package: cimg-dev
Version: 4.0.4+dfsg-1
Severity: wishlist

Dear maintainer,

TL;DR: I suggest changing the Depends on libopencv-dev to a
Recommends.

CImg is, according to the projects description, a "small" library. Yet
the Debian package cimg-dev does depend on libopencv-dev, which pulls in
another 500MB of packages (unpacked size).

CImg can use OpenCV if you define cimg_use_opencv, but it can be used
without it. I found 3 packages build-depending on cimg-dev (beads,
jkqtplotter, tiv), and none of them seems to utilize OpenCV. So removing
or demoting the libopencv-dev dependency to recommends/suggests should
not cause an issue.

I can successfully compile small examples from the CImg tutorial without
libopencv-dev installed.

Is there a reason did not find for a dependeny on libopencv-dev?
Otherwise I would suggest to demote the dependeny to a recommends, like
the other libraries useable by CImg.

The same goes for libimath-dev, but thas is only a small package
compared to OpenCV with dependencies.

Thanks,
    Ingo

-- System Information:
Distributor ID:	Devuan
Description:	Devuan GNU/Linux 7 (freia/ceres)
Release:	7
Codename:	freia ceres
Architecture: x86_64

Kernel: Linux 7.2.3-spatz20260903 (SMP w/4 CPU threads; PREEMPT)
Kernel taint flags: TAINT_FIRMWARE_WORKAROUND, TAINT_OOT_MODULE, TAINT_RANDSTRUCT
Locale: LANG=en_GB.UTF-8, LC_CTYPE=en_GB.UTF-8 (charmap=UTF-8), LANGUAGE=en_US:en
Shell: /bin/sh linked to /usr/bin/dash
Init: sysvinit (via /sbin/init)

Versions of packages cimg-dev depends on:
ii  libimath-dev   3.2.2-2+b1
ii  libx11-dev     2:1.8.13-1
ii  libxrandr-dev  2:1.5.4-1+b4

Versions of packages cimg-dev recommends:
ii  libcurl4-openssl-dev [libcurl4-dev]         8.22.0-1
ii  libfftw3-dev                                3.3.11-1
pn  libgraphicsmagick++1-dev | libmagick++-dev  <none>
pn  libheif-dev                                 <none>
pn  libopencv-dev                               <none>

Versions of packages cimg-dev suggests:
pn  cimg-doc       <none>
pn  cimg-examples  <none>
pn  lapack3-dev    <none>
ii  libtiff-dev    4.7.2-1
pn  xmedcon        <none>

-- no debconf information