rubygem-ruby-lxc build failure on EPEL7: "cp: cannot stat './usr/lib64/gems/ruby/ruby-lxc-1.2.2/gem.build_complete': No such file or directory"

[ganto]

Building the rubygem-ruby-lxc RPM with mock for EPEL 7 fails with:

Building target platforms: x86_64                                                                                                                                        
Building for target x86_64                                                                                                                                               
Executing(%prep): /bin/sh -e /var/tmp/rpm-tmp.ti81iR                                                                                                                     
+ umask 022                                                                                                                                                              
+ cd /builddir/build/BUILD                                                                                                                                               
+ gem unpack /builddir/build/SOURCES/ruby-lxc-1.2.2.gem                                                                                                                   
Unpacked gem: '/builddir/build/BUILD/ruby-lxc-1.2.2'                                                                                                                     
+ cd /builddir/build/BUILD                                                                                                                                               
+ cd ruby-lxc-1.2.2                                                                                                                                                       
+ /usr/bin/chmod -Rf a+rX,u+w,g-w,o-w .                                                                                                                                  
+ echo 'Patch #0 (ruby-lxc-1.2.2-Fix-build-with-LXC-3.0.patch):'                                                                                                         
Patch #0 (ruby-lxc-1.2.2-Fix-build-with-LXC-3.0.patch):                                                                                                                   
+ /usr/bin/cat /builddir/build/SOURCES/ruby-lxc-1.2.2-Fix-build-with-LXC-3.0.patch                                                                                        
+ /usr/bin/patch -p1 --fuzz=0                                                                                                                                            
patching file ext/lxc/lxc.c                                                                                                                                              
+ gem spec /builddir/build/SOURCES/ruby-lxc-1.2.2.gem -l --ruby                                                                                                          
+ exit 0                                                                                                                                                                 
Executing(%build): /bin/sh -e /var/tmp/rpm-tmp.hBK7mN                                                                                                                    
+ umask 022                                                                                                                                                              
+ cd /builddir/build/BUILD                                                                                                                                               
+ cd ruby-lxc-1.2.2                                                                                                                                                       
+ gem build ruby-lxc.gemspec                                                                                                                                              
WARNING:  licenses is empty                                                                                                                
  Successfully built RubyGem                                                                  
  Name: ruby-lxc
  Version: 1.2.2                                                                                                                                                          
  File: ruby-lxc-1.2.2.gem                                                                                                                                                
+ mkdir -p ./usr/share/gems                                                                                                                                               
+ CONFIGURE_ARGS='--with-cflags='\''-O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector-strong --param=ssp-buffer-size=4 -grecord-gcc-switches   -m$
4 -mtune=generic'\'' '
+ gem install -V --local --install-dir ./usr/share/gems --bindir ./usr/bin --force --document=ri,rdoc ruby-lxc-1.2.2.gem
Installing gem ruby-lxc-1.2.2
/builddir/build/BUILD/ruby-lxc-1.2.2/usr/share/gems/gems/ruby-lxc-1.2.2/ext/lxc/extconf.rb
/builddir/build/BUILD/ruby-lxc-1.2.2/usr/share/gems/gems/ruby-lxc-1.2.2/ext/lxc/lxc.c
/builddir/build/BUILD/ruby-lxc-1.2.2/usr/share/gems/gems/ruby-lxc-1.2.2/lib/lxc.rb
/builddir/build/BUILD/ruby-lxc-1.2.2/usr/share/gems/gems/ruby-lxc-1.2.2/lib/lxc/version.rb
Building native extensions.  This could take a while...
/usr/bin/ruby extconf.rb
checking for lxc_container_new() in -llxc... yes
checking for lxc/lxccontainer.h... yes
checking for rb_thread_call_without_gvl()... yes
checking for rb_thread_blocking_region()... yes
creating Makefile
make "DESTDIR="
gcc -I. -I/usr/include -I/usr/include/ruby/backward -I/usr/include -I. -DHAVE_LXC_LXCCONTAINER_H -DHAVE_RB_THREAD_CALL_WITHOUT_GVL -DHAVE_RB_THREAD_CALL_WITHOUT_GVL -DHA$
E_RB_THREAD_BLOCKING_REGION -DHAVE_RB_THREAD_BLOCKING_REGION    -fPIC -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector-strong --param=ssp-buffer$
size=4 -grecord-gcc-switches   -m64 -mtune=generic -Wall  -m64 -o lxc.o -c lxc.c
rm -f lxc.so
gcc -shared -o lxc.so lxc.o -L. -L/usr/lib64 -L. -Wl,-z,relro -fstack-protector -rdynamic -Wl,-export-dynamic  -m64  -lruby -llxc  -lpthread -lrt -ldl -lcrypt -lm   -lc
make "DESTDIR=" install
/usr/bin/mkdir -p ./.gem.20180608-27-1fjh1zt/lxc
exit > .RUBYARCHDIR.time
/usr/bin/install -c -m 0755 lxc.so ./.gem.20180608-27-1fjh1zt/lxc
unable to convert "\xC0" from ASCII-8BIT to UTF-8 for lib/lxc/lxc.so, skipping

Successfully installed ruby-lxc-1.2.2
Parsing documentation for ruby-lxc-1.2.2
Installing ri documentation for ruby-lxc-1.2.2
Installing darkfish documentation for ruby-lxc-1.2.2
1 gem installed
+ exit 0
Executing(%install): /bin/sh -e /var/tmp/rpm-tmp.LJdlmO
+ umask 022
+ cd /builddir/build/BUILD
+ '[' /builddir/build/BUILDROOT/rubygem-ruby-lxc-1.2.2-0.1.el7.x86_64 '!=' / ']'
+ rm -rf /builddir/build/BUILDROOT/rubygem-ruby-lxc-1.2.2-0.1.el7.x86_64
++ dirname /builddir/build/BUILDROOT/rubygem-ruby-lxc-1.2.2-0.1.el7.x86_64
+ mkdir -p /builddir/build/BUILDROOT
+ mkdir /builddir/build/BUILDROOT/rubygem-ruby-lxc-1.2.2-0.1.el7.x86_64
+ cd ruby-lxc-1.2.2
+ mkdir -p /builddir/build/BUILDROOT/rubygem-ruby-lxc-1.2.2-0.1.el7.x86_64/usr/share/gems
+ cp -a ./usr/share/gems/build_info ./usr/share/gems/cache ./usr/share/gems/doc ./usr/share/gems/gems ./usr/share/gems/specifications /builddir/build/BUILDROOT/rubygem-ru
by-lxc-1.2.2-0.1.el7.x86_64/usr/share/gems/
+ mkdir -p /builddir/build/BUILDROOT/rubygem-ruby-lxc-1.2.2-0.1.el7.x86_64/usr/lib64/gems/ruby/ruby-lxc-1.2.2
+ cp -a ./usr/lib64/gems/ruby/ruby-lxc-1.2.2/gem.build_complete ./usr/lib64/gems/ruby/ruby-lxc-1.2.2/lxc /builddir/build/BUILDROOT/rubygem-ruby-lxc-1.2.2-0.1.el7.x86_64/u
sr/lib64/gems/ruby/ruby-lxc-1.2.2/
cp: cannot stat './usr/lib64/gems/ruby/ruby-lxc-1.2.2/gem.build_complete': No such file or directory
cp: cannot stat './usr/lib64/gems/ruby/ruby-lxc-1.2.2/lxc': No such file or directory
error: Bad exit status from /var/tmp/rpm-tmp.LJdlmO (%install)


RPM build errors:
    Bad exit status from /var/tmp/rpm-tmp.LJdlmO (%install)
ERROR: Exception(SRPMS/rubygem-ruby-lxc-1.2.2-0.1.el7.src.rpm) Config(epel-7-x86_64) 0 minutes 48 seconds

The spec file was originally created with gem2rpm on Fedora 27 (ruby-2.4.4-88.fc27) and then manually adjusted to correctly manage the shared library and its dependencies. The EPEL 7 build environment still runs ruby-2.0.0.648-33.el7_4.