libsigrokcxx.pc has a "Requires" field listing "libsigrok" which
will cause libsigrok's "Requires.private" entries to be used/inherited
when 'pkg-config --libs --static libsigrokcxx' is used.
Description: C++ bindings for libsigrok
URL: http://www.sigrok.org
Requires: libsigrok glibmm-2.4
Description: C++ bindings for libsigrok
URL: http://www.sigrok.org
Requires: libsigrok glibmm-2.4
-Requires.private: @SR_PKGLIBS@
Version: @VERSION@
Libs: -L${libdir} -lsigrokcxx
Libs.private: -lm
Version: @VERSION@
Libs: -L${libdir} -lsigrokcxx
Libs.private: -lm