To track support of pkg-config in sage's dependencies:

• pari - no public bug tracker
• Provide pkg-config file simon-king-jena/SharedMeatAxe#2
• mpc - no public bug tracker
• mpfi - no public bug tracker
• Provide pkg-config file libntl/ntl#31
• pkg-config to make using libnormaliz easier; for determining the correct CPPFLAGS/CXXFLAGS/LDFLAGS etc Normaliz/Normaliz#417
• ecl - no public bug tracker
• Provide pkg-config file tscrim/coxeter#19
• giac - no public bug tracker
• bliss - no public bug tracker
• https://gitlab.com/janezkonc/mcqd/-/issues/2
• https://sourceforge.net/p/rankwidth/tickets/3/
• iml - no public bug tracker
• glpk - no public bug tracker
• brial-groebner
• ecm