Hi, Such an error I can not reproduce: https://www.cpantesters.org/cpan/report/6abf7f68-6d61-1014-8cbe-f6af8038f308
Tcl.xs:32:10: fatal error: tcl.h: No such file or directory 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 Tcl.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=\"1.16\" -DXS_VERSION=\"1.16\" "-IC:\STRAWB~1\perl\lib\CORE" Tcl.c yet indeed - there is no "-Isomething" is there; I am also using strawberry with gcc which comes with it; but in my case all is good, as long as I do have this in tclConfig.sh TCL_INCLUDE_SPEC='-IC:\apps\tcl-866-as86\include' C:\vad\perl-dev\tcl.pm>perl Makefile.PL tclsh=C:/apps/tcl-866-as86/bin/tclsh.exe tclConfig.sh=C:/apps/tcl-866-as86/lib/tclConfig.sh tcl_library=C:/apps/tcl-866-as86/lib/tcl8.6 tcl_version=8.6 Using config data in C:/apps/tcl-866-as86/lib/tclConfig.sh LIBS = C:\apps\tcl-866-as86\lib\tcl86t.lib INC = -IC:\apps\tcl-866-as86\include DEFINE = tclConfig.sh = C:/apps/tcl-866-as86/lib/tclConfig.sh Generating a gmake-style Makefile Writing Makefile for Tcl Writing MYMETA.yml and MYMETA.json "C:\apps\perl-5.26.0-32\perl\bin\perl.exe" -MExtUtils::Command::MM -e cp_nonempty -- Tcl.bs blib\arch\auto\Tcl\Tcl.bs 644 gcc -c -IC:\apps\tcl-866-as86\include -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=\"1.16\" -DXS_VERSION=\"1.16\" "-IC:\apps\perl-5.26.0-32\perl\lib\CORE" Tcl.c but we do have these lines I Makefile.PL now: ... $incpath = $tclcfg{TCL_INCLUDE_SPEC}; # https://www.cpantesters.org/cpan/report/18397198-6bf4-1014-85e5-4e79f459b9c5 # Tcl.xs:32:10: fatal error: tcl.h: No such file or directory if ($incpath) { my @tclh = grep {-f "$_/tcl.h"} $incpath=~/-I(\S+)/g; if ($#tclh==-1) { _die "incpath $incpath from your tclconfig $tclconfig does not provide tcl.h" } } else {_die "can not figure out incpath from your tclconfig $tclconfig"} How come this happen to avoid my otherwise perfect check?? Any ideas?