https://bugs.gentoo.org/837875

/var/tmp/portage/app-text/texlive-core-2021-r1/work/texlive-20210325-source/texk/web2c/mplibdir/pngout.w:63:10: fatal error: mplib.h: No such file or directory
   63 | #include "mplib.h"
      |          ^~~~~~~~~

--- texlive-20230311-source/texk/web2c/mplibdir/am/libmplib.am
+++ texlive-20230311-source/texk/web2c/mplibdir/am/libmplib.am
@@ -92,8 +92,8 @@
 $(nodist_libmplibcore_a_SOURCES): $(mpmathbinary_c_h) $(svgout_c_h) $(pngout_c_h)
 
 $(libmplibcore_a_OBJECTS): $(nodist_libmplibcore_a_SOURCES) $(KPATHSEA_DEPEND)  
-$(libmplibextramath_a_OBJECTS): $(nodist_libmplibextramath_a_SOURCES) $(KPATHSEA_DEPEND)  $(MPFR_DEPEND)
-$(libmplibbackends_a_OBJECTS): $(nodist_libmplibbackends_a_SOURCES) $(KPATHSEA_DEPEND) $(CAIRO_DEPEND) $(MPFR_DEPEND)
+$(libmplibextramath_a_OBJECTS): $(nodist_libmplibextramath_a_SOURCES) $(KPATHSEA_DEPEND)  $(MPFR_DEPEND) mplib.h
+$(libmplibbackends_a_OBJECTS): $(nodist_libmplibbackends_a_SOURCES) $(KPATHSEA_DEPEND) $(CAIRO_DEPEND) $(MPFR_DEPEND) mplib.h
 
 
 EXTRA_DIST += $(libmplib_web)