buildcaches: fix directory link relocation (#26948)

When relocating a binary distribution, Spack only checks files to see
if they are a link that needs to be relocated. Directories can be
such links as well, however, and need to undergo the same checks
and potential relocation.

lib/spack/spack/binary_distribution.py

@@ -608,6 +608,16 @@ def get_buildfile_manifest(spec):
     # Used by make_package_relative to determine binaries to change.
     for root, dirs, files in os.walk(spec.prefix, topdown=True):
         dirs[:] = [d for d in dirs if d not in blacklist]
+
+        # Directories may need to be relocated too.
+        for directory in dirs:
+            dir_path_name = os.path.join(root, directory)
+            rel_path_name = os.path.relpath(dir_path_name, spec.prefix)
+            if os.path.islink(dir_path_name):
+                link = os.readlink(dir_path_name)
+                if os.path.isabs(link) and link.startswith(spack.store.layout.root):
+                    data['link_to_relocate'].append(rel_path_name)
+
         for filename in files:
             path_name = os.path.join(root, filename)
             m_type, m_subtype = relocate.mime_type(path_name)

lib/spack/spack/test/bindist.py

@@ -200,12 +200,14 @@ def test_default_rpaths_create_install_default_layout(mirror_dir):
     into the default directory layout scheme.
     """
     gspec, cspec = Spec('garply').concretized(), Spec('corge').concretized()
+    sy_spec = Spec('symly').concretized()
 
     # Install 'corge' without using a cache
     install_cmd('--no-cache', cspec.name)
+    install_cmd('--no-cache', sy_spec.name)
 
     # Create a buildache
-    buildcache_cmd('create', '-au', '-d', mirror_dir, cspec.name)
+    buildcache_cmd('create', '-au', '-d', mirror_dir, cspec.name, sy_spec.name)
     # Test force overwrite create buildcache (-f option)
     buildcache_cmd('create', '-auf', '-d', mirror_dir, cspec.name)
 
@@ -219,7 +221,7 @@ def test_default_rpaths_create_install_default_layout(mirror_dir):
     uninstall_cmd('-y', '--dependents', gspec.name)
 
     # Test installing from build caches
-    buildcache_cmd('install', '-au', cspec.name)
+    buildcache_cmd('install', '-au', cspec.name, sy_spec.name)
 
     # This gives warning that spec is already installed
     buildcache_cmd('install', '-au', cspec.name)
@@ -247,10 +249,12 @@ def test_default_rpaths_install_nondefault_layout(mirror_dir):
     into the non-default directory layout scheme.
     """
     cspec = Spec('corge').concretized()
+    # This guy tests for symlink relocation
+    sy_spec = Spec('symly').concretized()
 
     # Install some packages with dependent packages
     # test install in non-default install path scheme
-    buildcache_cmd('install', '-au', cspec.name)
+    buildcache_cmd('install', '-au', cspec.name, sy_spec.name)
 
     # Test force install in non-default install path scheme
     buildcache_cmd('install', '-auf', cspec.name)

var/spack/repos/builtin.mock/packages/symly/package.py

@@ -0,0 +1,45 @@
+# Copyright 2013-2021 Lawrence Livermore National Security, LLC and other
+# Spack Project Developers. See the top-level COPYRIGHT file for details.
+#
+# SPDX-License-Identifier: (Apache-2.0 OR MIT)
+
+
+import os
+import sys
+
+from spack import *
+
+
+class Symly(Package):
+    """A toy package full of symlinks."""
+
+    homepage = "https://www.example.com"
+    has_code = False
+    version('3.0.0')
+
+    def install(self, spec, prefix):
+        symly_c = '''
+#include <stdio.h>
+
+int main() {
+    printf("I'm just here to give the build system something to do...");
+    return 0;
+}
+'''
+        mkdirp('%s/symly' % self.stage.source_path)
+        with open('%s/symly/symly.c' % self.stage.source_path, 'w') as f:
+            f.write(symly_c)
+        gcc = which('/usr/bin/gcc')
+        if sys.platform == 'darwin':
+            gcc = which('/usr/bin/clang')
+        mkdirp(prefix.bin)
+        mkdirp(prefix.lib64)
+        gcc('-o', 'symly.bin',
+            'symly/symly.c')
+        print("prefix.bin", prefix.bin)
+        copy('symly.bin', '%s/symly' % prefix.bin)
+        # create a symlinked file.
+        os.symlink('%s/symly' % prefix.bin,
+                   '%s/symly' % prefix.lib64)
+        # Create a symlinked directory.
+        os.symlink(prefix.bin, prefix.include)