enable ignoring missing dep in pkg config file

Makefile

@@ -38,7 +38,7 @@ bump:
 	@ruby -e 'path = STDIN.read.strip;File.write(path, File.read(path).sub(/^(Version: +)([0-9]+)(?:(?:\.)([0-9]+)){1,}/){|s|"#{$$1}#{$$2}.#{$$3.to_i + 1}"})' <<< getargv++.pc
 	@ruby -e 'path = STDIN.read.strip;File.write(path, File.read(path).sub(/^(VERSION=)([0-9]+)(?:(?:\.)([0-9]+)){1,}/){|s|"#{$$1}#{$$2}.#{$$3.to_i + 1}"})' <<< Makefile-variables
 	@ruby -e 'path = STDIN.read.strip;File.write(path, File.read(path).sub(/^(PROJECT_NUMBER += +)([0-9]+)(?:(?:\.)([0-9]+)){1,}/){|s|"#{$$1}#{$$2}.#{$$3.to_i + 1}"})' <<< doxygen.conf
-	@env PKG_CONFIG_PATH=. pkg-config --modversion getargv++
+	@env PKG_CONFIG_PATH=. pkg-config --define-variable=dep= --modversion getargv++
 
 tag:
 	git add -A

getargv++.pc

@@ -1,12 +1,13 @@
 prefix=/usr/local
 includedir=${prefix}/include/getargv++
 libdir=${prefix}/lib
+dep=getargv
 
 Name: getargv++
 Description: Library for getting the arguments of other processes.
 URL: https://getargv.narzt.cam/
 Version: 0.10
-Requires: getargv
+Requires: ${dep}
 Cflags: -I${includedir}
 Libs: -L${libdir} -lgetargv++
 # private is for static linking