Makefile for building an rpm works locally, but not in Jenkins - jenkins

Question

I have a makefile for building debian and rpm packages. I have two Jenkins environments, one for Ubuntu and one for CentOS. The debian package works no problem, and the rpm make command works on my machine, but not on Jenkins. Jenkins returns the following error:
cp: cannot stat /root/rpmbuild/SOURCES/myfile.file': No such file or directory
error: Bad exit status from /var/tmp/rpm-tmp.mII8KL (%install)
I was getting similar errors when developing the package but eventually figured everything out, and all was good. I think the problem may lie with $RPM_BUILD_ROOT, %{buildroot}, or _topdir options. Nothing I have tried has led me anywhere however.
Here is my (modified) Makefile:
# a list of tools we depend on and must install if they're missing
DEBTOOLS=/usr/bin/debuild-pbuilder
RPMTOOLS=/usr/bin/rpmbuild
# convenience target for "make deb"
deb: my-package_1.0_all.deb
# convenience target for "make rpm".
rpm: my-package-1.0-Public.x86_64.rpm
# the target package (on Ubuntu at least)
my-package_1.0_all.deb: $(DEBTOOLS)
cd my-package; debuild-pbuilder -us -uc
my-package-1.0-Public.x86_64.rpm: $(RPMTOOLS)
cd rpmbuild; rpmbuild -bb SPECS/my-package.spec
/usr/bin/debuild-pbuilder:
apt-get -y install pbuilder
/usr/bin/rpmbuild:
yum -y install rpm-build
This is my spec file:
Summary: My Package
Name: my-package
Version: 1.0
Release: Public
Group: Applications/System
License: Public
Requires: external-package
Source1: myfile.file
%description
blah blah
%files
%config /etc/myfile.file
%install
mkdir -p $RPM_BUILD_ROOT/etc/
cp %{SOURCE1} %{buildroot}/etc/myfile.file
%post
ln -sf /etc/myfile.file /etc/external-package.conf

Answer 1

The problem was in fact that the file wasn't being found (obviously). For me this had a lot to do with the confusing nature of building rpm files. When the make command is executed, and the rpmbuild command is called, I needed to be able to specify the directory. When reading the documentation, it was stated you could use rpmbuild -D '_topdir .' -bb path/to/spec.spec to set the _topdir variable to the local directory you call from. This made sense as . represents this in linux.
However the actual call needs to be
rpmbuild -D "_topdir `pwd`" -bb path/to/spec.spec
This doesn't look all that different except it is crucial to use double-quotes. Using this command will run the build within the directory you call it from. After this rpmbuild will copy and handle the files for you as it should (which is confusing in itself).