Remove use of stage symlinks

etc/spack/defaults/config.yaml

@@ -37,18 +37,26 @@ config:
 
   # Temporary locations Spack can try to use for builds.
   #
-  # Spack will use the first one it finds that exists and is writable.
-  # You can use $tempdir to refer to the system default temp directory
-  # (as returned by tempfile.gettempdir()).
+  # Recommended options are given below.
   #
-  # A value of $spack/var/spack/stage indicates that Spack should run
-  # builds directly inside its install directory without staging them in
+  # Builds can be faster in temporary directories on some (e.g., HPC) systems.
+  # Specifying `$tempdir` will ensure use of the system default temporary
+  # directory (as returned by `tempfile.gettempdir()`).  Spack will append
+  # `spack-stage` and, if the username is not already in the path, the value
+  # of `$user` to the path.  The latter is used to avoid conflicts between
+  # users in shared temporary spaces.
+  #
+  # Another option that prevents conflicts and potential permission issues is
+  # to specify `~/.spack/stage`, which ensures each user builds in their home
+  # directory.
+  #
+  # A more traditional path uses the value of `$spack/var/spack/stage`, which
+  # builds directly inside Spack's instance without staging them in a
   # temporary space.
   #
   # The build stage can be purged with `spack clean --stage`.
   build_stage:
-    - $tempdir
-    - $spack/var/spack/stage
+    - $tempdir/spack-stage
 
 
   # Cache directory for already downloaded source tarballs and archived

lib/spack/llnl/util/filesystem.py

@@ -347,12 +347,18 @@ def copy_tree(src, dest, symlinks=True, ignore=None, _permissions=False):
     else:
         tty.debug('Copying {0} to {1}'.format(src, dest))
 
-    mkdirp(dest)
+    abs_src = os.path.abspath(src)
+    abs_dest = os.path.abspath(dest)
+
+    # Stop early to avoid unnecessary recursion if being asked to copy from a
+    # parent directory.
+    if abs_dest.startswith(abs_src):
+        raise ValueError('Cannot copy ancestor directory {0} into {1}'.
+                         format(abs_src, abs_dest))
 
-    src = os.path.abspath(src)
-    dest = os.path.abspath(dest)
+    mkdirp(dest)
 
-    for s, d in traverse_tree(src, dest, order='pre',
+    for s, d in traverse_tree(abs_src, abs_dest, order='pre',
                               follow_symlinks=not symlinks,
                               ignore=ignore,
                               follow_nonexisting=True):
@@ -361,7 +367,7 @@ def copy_tree(src, dest, symlinks=True, ignore=None, _permissions=False):
             if symlinks:
                 target = os.readlink(s)
                 if os.path.isabs(target):
-                    new_target = re.sub(src, dest, target)
+                    new_target = re.sub(abs_src, abs_dest, target)
                     if new_target != target:
                         tty.debug("Redirecting link {0} to {1}"
                                   .format(target, new_target))

lib/spack/spack/cmd/location.py

@@ -14,6 +14,7 @@
 import spack.environment
 import spack.paths
 import spack.repo
+import spack.stage
 
 description = "print out locations of packages and spack directories"
 section = "basic"
@@ -76,7 +77,7 @@ def location(parser, args):
         print(spack.repo.path.first_repo().root)
 
     elif args.stages:
-        print(spack.paths.stage_path)
+        print(spack.stage.get_stage_root())
 
     else:
         specs = spack.cmd.parse_specs(args.spec)

lib/spack/spack/compilers/clang.py

@@ -15,6 +15,7 @@
 from spack.compiler import Compiler, UnsupportedCompilerFlag
 from spack.util.executable import Executable
 from spack.version import ver
+import spack.stage
 
 
 #: compiler symlink mappings for mixed f77 compilers
@@ -282,7 +283,7 @@ def setup_custom_environment(self, pkg, env):
             raise OSError(msg)
 
         real_root = os.path.dirname(os.path.dirname(real_root))
-        developer_root = os.path.join(spack.paths.stage_path,
+        developer_root = os.path.join(spack.stage.get_stage_root(),
                                       'xcode-select',
                                       self.name,
                                       str(self.version))

lib/spack/spack/config.py

@@ -101,6 +101,7 @@
         'checksum': True,
         'dirty': False,
         'build_jobs': min(16, multiprocessing.cpu_count()),
+        'build_stage': '$spack/var/spack/stage',
     }
 }
 
@@ -439,10 +440,10 @@ def get_config(self, section, scope=None):
             scopes = [self._validate_scope(scope)]
 
         merged_section = syaml.syaml_dict()
-        for scope in scopes:
+        for scope_ in scopes:
             # read potentially cached data from the scope.
 
-            data = scope.get_section(section)
+            data = scope_.get_section(section)
 
             # Skip empty configs
             if not data or not isinstance(data, dict):

lib/spack/spack/package.py

@@ -1756,9 +1756,7 @@ def check_for_unfinished_installation(
                 else:
                     partial = True
 
-        stage_is_managed_in_spack = self.stage.path.startswith(
-            spack.paths.stage_path)
-        if restage and stage_is_managed_in_spack:
+        if restage and self.stage.managed_by_spack:
             self.stage.destroy()
             self.stage.create()
 

lib/spack/spack/patch.py

@@ -194,9 +194,11 @@ def fetch(self, stage):
         fetcher = fs.URLFetchStrategy(self.url, fetch_digest)
         mirror = os.path.join(
             os.path.dirname(stage.mirror_path),
+            'mirror-stage',
             os.path.basename(self.url))
 
-        self.stage = spack.stage.Stage(fetcher, mirror_path=mirror)
+        self.stage = spack.stage.Stage(fetcher, path=os.path.dirname(mirror),
+                                       mirror_path=mirror)
         self.stage.create()
         self.stage.fetch()
         self.stage.check()

lib/spack/spack/paths.py

@@ -38,7 +38,6 @@
 test_path             = os.path.join(module_path, "test")
 hooks_path            = os.path.join(module_path, "hooks")
 var_path              = os.path.join(prefix, "var", "spack")
-stage_path            = os.path.join(var_path, "stage")
 repos_path            = os.path.join(var_path, "repos")
 share_path            = os.path.join(prefix, "share", "spack")