Makefile: unexport PERL_MM_OPT

Compilation of Perl-related packages fails if `PERL_MM_OPT` is defined.

We previously issued an error in this case.
Instead, simply `unexport` the variable.

Signed-off-by: Gleb Mazovetskiy <glex.spb@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

Makefile

@@ -396,6 +396,9 @@ unexport DESTDIR
 # Causes breakage with packages that needs host-ruby
 unexport RUBYOPT
 
+# Compilation of perl-related packages will fail otherwise
+unexport PERL_MM_OPT
+
 include package/pkg-utils.mk
 include package/doc-asciidoc.mk
 

support/dependencies/dependencies.sh

@@ -46,15 +46,6 @@ case ":${PATH:-unset}:" in
 	;;
 esac
 
-if test -n "$PERL_MM_OPT" ; then
-	echo
-	echo "You have PERL_MM_OPT defined because Perl local::lib"
-	echo "is installed on your system. Please unset this variable"
-	echo "before starting Buildroot, otherwise the compilation of"
-	echo "Perl related packages will fail"
-	exit 1
-fi
-
 check_prog_host()
 {
 	prog="$1"