RE: fatal error: tcl.h: No such file or directory

> From: Konovalov, Vadim
>=20
> Hi,
>=20
> Such an error I can not reproduce:
> https://www.cpantesters.org/cpan/report/6abf7f68-6d61-1014-8cbe-f6af8038f=
308
>=20
> Tcl.xs:32:10: fatal error: tcl.h: No such file or directory

C:\vad\perl-dev\tcl.pm>gmake INC=3D
cp Tcl.pm blib\lib\Tcl.pm
Running Mkbootstrap for Tcl ()
"C:\apps\perl-5.26.0-32\perl\bin\perl.EXE" -MExtUtils::Command -e chmod -- =
644 "Tcl.bs"
"C:\apps\perl-5.26.0-32\perl\bin\perl.EXE" -MExtUtils::Command::MM -e cp_no=
nempty -- Tcl.bs blib\arch\auto\Tcl\Tcl.bs 64
4
"C:\apps\perl-5.26.0-32\perl\bin\perl.EXE" "C:\apps\perl-5.26.0-32\perl\lib=
\ExtUtils/xsubpp"  -typemap C:\apps\perl-5.26
.0-32\perl\lib\ExtUtils\typemap -typemap C:\vad\perl-dev\tcl.pm\typemap  Tc=
l.xs > Tcl.xsc
Please specify prototyping behavior for Tcl.xs (see perlxs manual)
"C:\apps\perl-5.26.0-32\perl\bin\perl.EXE" -MExtUtils::Command -e mv -- Tcl=
.xsc Tcl.c
gcc -c   -s -O2 -DWIN32 -D__USE_MINGW_ANSI_STDIO -DPERL_TEXTMODE_SCRIPTS -D=
PERL_IMPLICIT_CONTEXT -DPERL_IMPLICIT_SYS -DU
SE_PERLIO -fwrapv -fno-strict-aliasing -mms-bitfields -s -O2   -DVERSION=3D=
\"1.16\" -DXS_VERSION=3D\"1.16\"  "-IC:\apps\perl
-5.26.0-32\perl\lib\CORE"   Tcl.c
Tcl.xs:32:10: fatal error: tcl.h: No such file or directory
 #include <tcl.h>
          ^~~~~~~
compilation terminated.
gmake.EXE: *** [Makefile:338: Tcl.o] Error 1

I wonder if dmake have such a behaviour that it undefines INC?
Or what?
How to avoid?

>=20
> I see in log:
> Please specify prototyping behavior for Tcl.xs (see perlxs manual)
> "C:\Strawberry\perl\bin\perl.exe" -MExtUtils::Command -e mv -- Tcl.xsc Tc=
l.c
> gcc -c	 -s -O2 -DWIN32 -D__USE_MINGW_ANSI_STDIO -DPERL_TEXTMODE_SCRIPTS
> -DPERL_IMPLICIT_CONTEXT -DPERL_IMPLICIT_SYS -DUSE_PERLIO -fwrapv
> -fno-strict-aliasing -mms-bitfields -s -O2   -DVERSION=3D\"1.16\"
> -DXS_VERSION=3D\"1.16\"  "-IC:\STRAWB~1\perl\lib\CORE"   Tcl.c
>=20