Support downloading of symlinked tarballs

build/sage_bootstrap/package.py

@@ -147,6 +147,25 @@ def tarball_filename(self):
         """
         return self.tarball_pattern.replace('VERSION', self.version)
 
+    @property
+    def tarball_package(self):
+        """
+        Return the canonical package for the tarball
+
+        This is almost always equal to ``self`` except if the package
+        or the ``checksums.ini`` file is a symbolic link. In that case,
+        the package of the symbolic link is returned.
+
+        OUTPUT:
+
+        A ``Package`` instance
+        """
+        n = self.__tarball_package_name
+        if n == self.name:
+            return self
+        else:
+            return type(self)(n)
+
     @property
     def version(self):
         """
@@ -211,6 +230,8 @@ def _init_checksum(self):
         self.__sha1 = result.get('sha1', None)
         self.__cksum = result.get('cksum', None)
         self.__tarball_pattern = result['tarball']
+        # Name of the directory containing the checksums.ini file
+        self.__tarball_package_name = os.path.realpath(checksums_ini).split(os.sep)[-2]
 
     VERSION_PATCHLEVEL = re.compile('(?P<version>.*)\.p(?P<patchlevel>[0-9]+)')
 

build/sage_bootstrap/tarball.py

@@ -56,7 +56,7 @@ def __init__(self, tarball_name, package=None):
             self.__package = None
             for pkg in Package.all():
                 if pkg.tarball_filename == tarball_name:
-                    self.__package = pkg
+                    self.__package = pkg.tarball_package
             if self.package is None:
                 error = 'tarball {0} is not referenced by any Sage package'.format(tarball_name)
                 log.error(error)