On building mingw32-qt6-imageformat for MinGW it turned out that the mentioned
package does not have pkgconfig support 

~/osc/home:rhabacker:branches:windows:mingw:win32:Qt65/mingw32-qt6-imageformats>
osc build openSUSE_Leap_15.5 -j12
Building mingw32-qt6-imageformats.spec for openSUSE_Leap_15.5/x86_64
Getting buildconfig from server and store to
/home/osc/home:rhabacker:branches:windows:mingw:win32:Qt65/mingw32-qt6-imageformats/.osc/_buildconfig-openSUSE_Leap_15.5-x86_64
Getting buildinfo from server and store to
/home/osc/home:rhabacker:branches:windows:mingw:win32:Qt65/mingw32-qt6-imageformats/.osc/_buildinfo-openSUSE_Leap_15.5-x86_64.xml
buildinfo is broken... it says:
unresolvable: nothing provides mingw32(pkg:libmng)

Bug ID	1213028
Summary	windows:mingw:win{32\|64}/mingw{32\|64}-libmng: no pkgconfig support
Classification	openSUSE
Product	openSUSE.org
Version	unspecified
Hardware	Other
OS	Other
Status	NEW
Severity	Normal
Priority	P5 - None
Component	3rd party software
Assignee	fstrba@suse.com
Reporter	ralf.habacker@freenet.de
QA Contact	screening-team-bugs@suse.de
CC	fridrich.strba@bluewin.ch, hib@hiberis.nl, mkbosmans@gmail.com
Target Milestone	---
Found By	---
Blocker	---