how_to_install_singularity_into_custom_loc

# download singularity:

wget https://github.com/sylabs/singularity/releases/download/v3.0.1/singularity-3.0.1.tar.gz

# install missing deps

yum install git libseccomp-devel

# unpack tarball

tar -xvf ./singularity-3.0.1.tar.gz

# edit specfile - before "description" section insert the prefix:

59 #prefix for KOIOS
60 %define _prefix /opt/singularity/%{version}
61 %define _sysconfdir %{_prefix}/etc
62 %define _sharedstatedir %{_prefix}/var/lib
63 %define _localstatedir %{_prefix}/var
64 
65 
66 %description
67 Singularity provides functionality to make portable

# ..and before make DESTDIR .. place mkdir statements to ensure all subdirs in our directory will be present.
 
115 mkdir -p %{_prefix}     #create prefix dir
116 mkdir -p %{_exec_prefix}
117 mkdir -p %{_bindir}
118 mkdir -p %{_libexecdir}
119 mkdir -p %{_sysconfdir}
120 mkdir -p %{_sharedstatedir}
121 mkdir -p %{_localstatedir}
122 mkdir -p %{_libdir}
123 mkdir -p %{_mandir}
124 
125 mkdir -p $RPM_BUILD_ROOT%{_exec_prefix}/share/man/man1

# and specify our site-specific build suffix to recognize it..:

Release: 1%{?dist}.KOIOS

# backup the old tar.gz:

mv ./singularity-3.0.1.tar.gz ./singularity-3.0.1.tar.gz_orig

# and pack updated tar.gz:

tar -zcvf ./singularity-3.0.1.tar.gz ./singularity

# produce RPM:

rpmbuild -tb singularity-3.0.1.tar.gz