Apparently the Perl XS header order is significant. clang-format changed this and caused issues.
I could not see much in the way of this being documented as required.
I am also not clear on why this built fine on Travis. I encountered issues building on both Ubuntu Bionic and Trusty in my testing prior to this fix. I used the OS packaged Perls though, so the environment is different compared to Travis.
Apparently the Perl XS header order is significant. clang-format changed this and caused issues.
I could not see much in the way of this being documented as required.
I am also not clear on why this built fine on Travis. I encountered issues building on both Ubuntu Bionic and Trusty in my testing prior to this fix. I used the OS packaged Perls though, so the environment is different compared to Travis.