It is true that GraphicsMagick can not be 100% compatible with
ImageMagick (and makes no effort to follow ImageMagick changes), except
for the precise version it branched from. It is also true that
ImageMagick is not compatible with prior ImageMagick versions and
continues to change its interfaces and behavior rapidly.
Debian has been distributing ImageMagick 6, which is a sort of LTS
version of ImageMagick, but ImageMagick 7 differs from ImageMagick 6 in
many ways, and in fact it has deprecated the 'convert' command and
prefers to be invoked as 'magick' ("WARNING: The convert command is
deprecated in IMv7, use "magick" instead of "convert" or "magick convert"").
It appears that ImageMagick6 changed its syntax from '-map netscape:' to
'-remap netscape:', and eliminated '-map' entirely.
Bob (GraphicsMagick Maintainer)
On 6/28/25 14:03, James Lu wrote:
Hi maintainer,
*Please* consider getting rid of this Provides. It's been causing
sporadic build failures for 18 years! graphicsmagick forked from
imagemagick over 20 years ago and it's clear that they've diverged far
too much for graphicsmagick to be a drop-in replacement. (This
shouldn't even be a surprise, considering the time frame.)
Anyways, this Provides is causing icoextract builds in experimental to
fail[1]. I am not sure why this package got picked as a build-dep by
the buildd to begin with, but even when I remove a bunch of
unsupported convert flags, I am blocked because graphicsmagick does
not support creating .ICO files while imagemagick does[2]:
$ make testapp.ico
convert testapp.png -resize 16x16 tmp-testapp-16.bmp
convert testapp.png -resize 32x32 tmp-testapp-32.bmp
convert testapp.png -resize 48x48 tmp-testapp-48.bmp
convert testapp.png tmp-testapp*.bmp testapp.ico
convert: No encode delegate for this image format (ICO).
make: *** [Makefile:15: testapp.ico] Error 1
root@86890e20afd5:/tmp/src/tests# convert testapp.png testapp.ico
convert: No encode delegate for this image format (ICO).
Policy 7.5 suggests I can work around this with a versioned
dependency[3] on imagemagick, but I don't think I should need one to
begin with. When I build-dep on something I expect to get that, or
something that's actually compatible :/
[1]:
https://buildd.debian.org/status/fetch.php?pkg=icoextract&arch=all&ver=0.2.0-1&stamp=1750623272&raw=0
[2]: https://sourceforge.net/p/graphicsmagick/feature-requests/71/
[3]:
https://www.debian.org/doc/debian-policy/ch-relationships.html#virtual-packages-provides
Best,
James
