Use bundled modules when bootstrapping

perl-Math-BigInt.spec

@@ -13,9 +13,36 @@ BuildRequires:  coreutils
 BuildRequires:  findutils
 BuildRequires:  make
 BuildRequires:  perl
+# This core module must be buildable without non-core modules at bootstrap.
+%if %{defined perl_bootstrap}
+BuildRequires:  perl(Config)
+BuildRequires:  perl(Cwd)
+BuildRequires:  perl(ExtUtils::MakeMaker)
+# ExtUtils::Manifest not used
+# ExtUtils::MM_Cygwin not used
+BuildRequires:  perl(ExtUtils::MM_Unix)
+# ExtUtils::MM_Win32 not used
+BuildRequires:  perl(Fcntl)
+# File::Basename not used
+BuildRequires:  perl(File::Find)
+BuildRequires:  perl(File::Path)
+# File::Spec not used
+# File::Temp not used
+# FileHandle not used
+BuildRequires:  perl(FindBin)
+# JSON not used
+# LWP::Simple not used
+# Module::Build not used
+# Net::FTP not used
+# Parse::CPAN::Meta not used
+# Socket not used
+BuildRequires:  perl(vars)
+# YAML::Tiny not used
+%else
 BuildRequires:  perl(inc::Module::Install)
 BuildRequires:  perl(Module::Install::Metadata)
 BuildRequires:  perl(Module::Install::WriteAll)
+%endif
 BuildRequires:  perl(strict)
 BuildRequires:  sed
 # Run-time:
@@ -47,9 +74,12 @@ This provides Perl modules for arbitrary-size integer and float mathematics.
 
 %prep
 %setup -q -n Math-BigInt-%{cpan_version}
+# This core module must be buildable without non-core modules at bootstrap.
+%if !%{defined perl_bootstrap}
 # Remove bundled modules
 rm -r inc
 sed -i -e '/^inc\//d' MANIFEST
+%endif
 # Correct permissions
 find . -type f -exec chmod -x {} +
 
@@ -75,3 +105,4 @@ make test
 %changelog
 * Mon Nov 02 2015 Petr Pisar <ppisar@redhat.com> 1.9997.07-354
 - Specfile autogenerated by cpanspec 1.78.
+- Use bundled modules when bootstrapping