def runtime(self, _from='0'):
        """Generate the set of instructions to install the runtime specific
        components from a build in a previous stage.

        # Examples

        ```python
        p = pgi(...)
        Stage0 += p
        Stage1 += p.runtime()
        ```
        """
        self.rt += comment('PGI compiler')

        if self.__runtime_ospackages:
            self.rt += packages(ospackages=self.__runtime_ospackages)

        pgi_path = posixpath.join(self.__basepath, self.__version)
        src_path = pgi_path
        if (Version(self.__version) >= Version('19.4') and
            hpccm.config.g_cpu_arch == cpu_arch.X86_64):
            # Too many levels of symlinks for the Docker builder to
            # handle, so use the real path
            src_path = posixpath.join(self.__basepath_llvm, self.__version)
        self.rt += copy(_from=_from,
                        src=posixpath.join(src_path, 'REDIST', '*.so*'),
                        dest=posixpath.join(pgi_path, 'lib', ''))

        # REDIST workaround for incorrect libcudaforwrapblas.so
        # symlink
        if (Version(self.__version) >= Version('18.10') and
            Version(self.__version) < Version('19.10') and
            hpccm.config.g_cpu_arch == cpu_arch.X86_64):
            self.rt += copy(_from=_from,
                            src=posixpath.join(pgi_path, 'lib',
                                               'libcudaforwrapblas.so'),
                            dest=posixpath.join(pgi_path, 'lib',
                                                'libcudaforwrapblas.so'))

        if self.__mpi:
            mpi_path = posixpath.join(pgi_path, 'mpi', 'openmpi')
            if Version(self.__version) >= Version('19.4'):
                mpi_path = posixpath.join(pgi_path, 'mpi', 'openmpi-3.1.3')
            self.rt += copy(_from=_from, src=mpi_path, dest=mpi_path)

        if self.__runtime_commands:
            self.rt += shell(commands=self.__runtime_commands)

        self.rt += environment(variables=self.environment_step(runtime=True))
        return str(self.rt)
Generate the set of instructions to install the runtime specific
        components from a build in a previous stage.

        # Examples

        ```python
        p = pgi(...)
        Stage0 += p
        Stage1 += p.runtime()
        ```
        
hpccm/building_blocks/pgi.py