[MacPorts] #57756: mathgl: fatal error: 'Fl/Fl_RGB_Image.H' file not found

[MacPorts]

#57756: mathgl: fatal error: 'Fl/Fl_RGB_Image.H' file not found
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Reporter: ryandesign | Owner: Schamschula
Type: defect | Status: assigned
Priority: Normal | Milestone:
Component: ports | Version:
Keywords: | Port: mathgl
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[https://build.macports.org/builders/ports-10.12_x86_64-builder/builds/75584/steps
/install-port/logs/stdio mathgl fails to build on case-sensitive
filesystems] like the buildbot workers':

{{{
/opt/local/var/macports/build/_opt_bblocal_var_buildworker_ports_build_ports_math_mathgl/mathgl/work/mathgl-2.4.2.1/widgets/image.h:21:10:
fatal error: 'Fl/Fl_RGB_Image.H' file not found
#include <Fl/Fl_RGB_Image.H>
^~~~~~~~~~~~~~~~~~~
1 error generated.
}}}

The directory name is FL, not Fl.