diff --git a/swh/loader/svn/ra.py b/swh/loader/svn/ra.py
index ad33411..0d0405e 100644
--- a/swh/loader/svn/ra.py
+++ b/swh/loader/svn/ra.py
@@ -1,644 +1,653 @@
 # Copyright (C) 2016-2021  The Software Heritage developers
 # See the AUTHORS file at the top-level directory of this distribution
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
 """Remote Access client to svn server.
 
 """
 
 from __future__ import annotations
 
 import codecs
 import dataclasses
+import logging
 import os
 import shutil
 import tempfile
 from typing import (
     TYPE_CHECKING,
     Any,
     BinaryIO,
     Callable,
     Dict,
     List,
     Optional,
     Tuple,
     Union,
     cast,
 )
 
 import click
 from subvertpy import delta, properties
 from subvertpy.ra import Auth, RemoteAccess, get_username_provider
 
 from swh.model import from_disk, hashutil
 from swh.model.model import Content, Directory, SkippedContent
 
 if TYPE_CHECKING:
     from swh.loader.svn.svn import SvnRepo
 
 _eol_style = {"native": b"\n", "CRLF": b"\r\n", "LF": b"\n", "CR": b"\r"}
 
+logger = logging.getLogger(__name__)
+
 
 def _normalize_line_endings(lines: bytes, eol_style: str = "native") -> bytes:
     r"""Normalize line endings to unix (\\n), windows (\\r\\n) or mac (\\r).
 
     Args:
         lines: The lines to normalize
 
         eol_style: The line ending format as defined for
             svn:eol-style property. Acceptable values are 'native',
             'CRLF', 'LF' and 'CR'
 
     Returns:
         Lines with endings normalized
     """
     if eol_style in _eol_style:
         lines = lines.replace(_eol_style["CRLF"], _eol_style["LF"]).replace(
             _eol_style["CR"], _eol_style["LF"]
         )
         if _eol_style[eol_style] != _eol_style["LF"]:
             lines = lines.replace(_eol_style["LF"], _eol_style[eol_style])
 
     return lines
 
 
 def apply_txdelta_handler(
     sbuf: bytes, target_stream: BinaryIO
 ) -> Callable[[Any, bytes, BinaryIO], None]:
     """Return a function that can be called repeatedly with txdelta windows.
     When done, closes the target_stream.
 
     Adapted from subvertpy.delta.apply_txdelta_handler to close the
     stream when done.
 
     Args:
         sbuf: Source buffer
         target_stream: Target stream to write to.
 
     Returns:
         Function to be called to apply txdelta windows
 
     """
 
     def apply_window(
         window: Any, sbuf: bytes = sbuf, target_stream: BinaryIO = target_stream
     ):
         if window is None:
             target_stream.close()
             return  # Last call
         patch = delta.apply_txdelta_window(sbuf, window)
         target_stream.write(patch)
 
     return apply_window
 
 
 def read_svn_link(data: bytes) -> Tuple[bytes, bytes]:
     """Read the svn link's content.
 
     Args:
         data: svn link's raw content
 
     Returns:
         The tuple of (filetype, destination path)
 
     """
     split_byte = b" "
     first_line = data.split(b"\n")[0]
     filetype, *src = first_line.split(split_byte)
     target = split_byte.join(src)
     return filetype, target
 
 
 def is_file_an_svnlink_p(fullpath: bytes) -> Tuple[bool, bytes]:
     """Determine if a filepath is an svnlink or something else.
 
     Args:
         fullpath: Full path to the potential symlink to check
 
     Returns:
         Tuple containing a boolean value to determine if it's indeed a symlink
         (as per svn) and the link target.
 
     """
     if os.path.islink(fullpath):
         return False, b""
     with open(fullpath, "rb") as f:
         filetype, src = read_svn_link(f.read())
         return filetype == b"link", src
 
 
 def _ra_codecs_error_handler(e: UnicodeError) -> Tuple[Union[str, bytes], int]:
     """Subvertpy may fail to decode to utf-8 the user svn properties.  As
        they are not used by the loader, return an empty string instead
        of the decoded content.
 
     Args:
         e: exception raised during the svn properties decoding.
 
     """
     return "", cast(UnicodeDecodeError, e).end
 
 
 DEFAULT_FLAG = 0
 EXEC_FLAG = 1
 NOEXEC_FLAG = 2
 
 SVN_PROPERTY_EOL = "svn:eol-style"
 
 
 @dataclasses.dataclass
 class FileState:
     """Persists some file states (eg. end of lines style) across revisions while
     replaying them."""
 
     eol_style: Optional[str] = None
     """EOL state check mess"""
 
     svn_special_path_non_link_data: Optional[bytes] = None
     """keep track of non link file content with svn:special property set"""
 
     # default value: 0, 1: set the flag, 2: remove the exec flag
     executable: int = DEFAULT_FLAG
     """keep track if file is executable when setting svn:executable property"""
 
     link: bool = False
     """keep track if file is a svn link when setting svn:special property"""
 
 
 class FileEditor:
     """File Editor in charge of updating file on disk and memory objects.
 
     """
 
     __slots__ = [
         "directory",
         "path",
         "fullpath",
         "executable",
         "link",
         "state",
         "svnrepo",
     ]
 
     def __init__(
         self,
         directory: from_disk.Directory,
         rootpath: bytes,
         path: bytes,
         state: FileState,
         svnrepo: SvnRepo,
     ):
         self.directory = directory
         self.path = path
         self.fullpath = os.path.join(rootpath, path)
         self.state = state
         self.svnrepo = svnrepo
 
     def change_prop(self, key: str, value: str) -> None:
         if key == properties.PROP_EXECUTABLE:
             if value is None:  # bit flip off
                 self.state.executable = NOEXEC_FLAG
             else:
                 self.state.executable = EXEC_FLAG
         elif key == properties.PROP_SPECIAL:
             # Possibly a symbolic link. We cannot check further at
             # that moment though, patch(s) not being applied yet
             self.state.link = value is not None
         elif key == SVN_PROPERTY_EOL:
             # backup end of line style for file
             self.state.eol_style = value
 
     def __make_symlink(self, src: bytes) -> None:
         """Convert the svnlink to a symlink on disk.
 
         This function expects self.fullpath to be a svn link.
 
         Args:
             src: Path to the link's source
 
         Return:
             tuple: The svnlink's data tuple:
 
                 - type (should be only 'link')
                 - <path-to-src>
 
         """
         os.remove(self.fullpath)
         os.symlink(src=src, dst=self.fullpath)
 
     def __make_svnlink(self) -> bytes:
         """Convert the symlink to a svnlink on disk.
 
         Return:
             The symlink's svnlink data (``b'type <path-to-src>'``)
 
         """
         # we replace the symlink by a svnlink
         # to be able to patch the file on future commits
         src = os.readlink(self.fullpath)
         os.remove(self.fullpath)
         sbuf = b"link " + src
         with open(self.fullpath, "wb") as f:
             f.write(sbuf)
         return sbuf
 
     def apply_textdelta(self, base_checksum) -> Callable[[Any, bytes, BinaryIO], None]:
         if os.path.lexists(self.fullpath):
             if os.path.islink(self.fullpath):
                 # svn does not deal with symlink so we transform into
                 # real svn symlink for potential patching in later
                 # commits
                 sbuf = self.__make_svnlink()
                 self.state.link = True
             else:
                 with open(self.fullpath, "rb") as f:
                     sbuf = f.read()
         else:
             sbuf = b""
 
         t = open(self.fullpath, "wb")
         return apply_txdelta_handler(sbuf, target_stream=t)
 
     def close(self) -> None:
         """When done with the file, this is called.
 
         So the file exists and is updated, we can:
 
         - adapt accordingly its execution flag if any
         - compute the objects' checksums
         - replace the svnlink with a real symlink (for disk
           computation purposes)
 
         """
 
         if self.state.link:
             # can only check now that the link is a real one
             # since patch has been applied
             is_link, src = is_file_an_svnlink_p(self.fullpath)
             if is_link:
                 self.__make_symlink(src)
             elif not os.path.isdir(self.fullpath):  # not a real link ...
                 # when a file with the svn:special property set is not a svn link,
                 # the svn export operation might extract a truncated version of it
                 # if it is a binary file, so ensure to produce the same file as the
                 # export operation.
                 with open(self.fullpath, "rb") as f:
                     content = f.read()
                 self.svnrepo.client.export(
                     os.path.join(self.svnrepo.remote_url.encode(), self.path),
                     to=self.fullpath,
                     rev=self.svnrepo.swhreplay.editor.revnum,
                     ignore_keywords=True,
                     overwrite=True,
                 )
                 with open(self.fullpath, "rb") as f:
                     exported_data = f.read()
                     if exported_data != content:
                         # keep track of original file content in order to restore
                         # it if the svn:special property gets unset in another revision
                         self.state.svn_special_path_non_link_data = content
         elif os.path.islink(self.fullpath):
             # path was a symbolic link in previous revision but got the property
             # svn:special unset in current one, revert its content to svn link format
             self.__make_svnlink()
         elif self.state.svn_special_path_non_link_data is not None:
             # path was a non link file with the svn:special property previously set
             # and got truncated on export, restore its original content
             with open(self.fullpath, "wb") as f:
                 f.write(self.state.svn_special_path_non_link_data)
                 self.state.svn_special_path_non_link_data = None
 
         is_link = os.path.islink(self.fullpath)
         if not is_link:  # if a link, do nothing regarding flag
             if self.state.executable == EXEC_FLAG:
                 os.chmod(self.fullpath, 0o755)
             elif self.state.executable == NOEXEC_FLAG:
                 os.chmod(self.fullpath, 0o644)
 
         # And now compute file's checksums
         if self.state.eol_style and not is_link:
             # ensure to normalize line endings as defined by svn:eol-style
             # property to get the same file checksum as after an export
             # or checkout operation with subversion
             with open(self.fullpath, "rb") as f:
                 data = f.read()
                 data = _normalize_line_endings(data, self.state.eol_style)
                 mode = os.lstat(self.fullpath).st_mode
                 self.directory[self.path] = from_disk.Content.from_bytes(
                     mode=mode, data=data
                 )
         else:
             self.directory[self.path] = from_disk.Content.from_file(path=self.fullpath)
 
 
 class DirEditor:
     """Directory Editor in charge of updating directory hashes computation.
 
     This implementation includes empty folder in the hash computation.
 
     """
 
     __slots__ = ["directory", "rootpath", "path", "file_states", "svnrepo"]
 
     def __init__(
         self,
         directory: from_disk.Directory,
         rootpath: bytes,
         path: bytes,
         file_states: Dict[bytes, FileState],
         svnrepo: SvnRepo,
     ):
         self.directory = directory
         self.rootpath = rootpath
         self.path = path
         # build directory on init
         os.makedirs(rootpath, exist_ok=True)
         self.file_states = file_states
         self.svnrepo = svnrepo
 
     def remove_child(self, path: bytes) -> None:
         """Remove a path from the current objects.
 
         The path can be resolved as link, file or directory.
 
         This function takes also care of removing the link between the
         child and the parent.
 
         Args:
             path: to remove from the current objects.
 
         """
         try:
             entry_removed = self.directory[path]
         except KeyError:
             entry_removed = None
         else:
             del self.directory[path]
             fpath = os.path.join(self.rootpath, path)
             if isinstance(entry_removed, from_disk.Directory):
                 shutil.rmtree(fpath)
             else:
                 os.remove(fpath)
 
         # when deleting a directory ensure to remove any svn property for the
         # file it contains as they can be added again later in another revision
         # without the same property set
         fullpath = os.path.join(self.rootpath, path)
         for state_path in list(self.file_states):
             if state_path.startswith(fullpath + b"/"):
                 del self.file_states[state_path]
 
     def update_checksum(self) -> None:
         """Update the root path self.path's checksums according to the
         children's objects.
 
         This function is expected to be called when the folder has
         been completely 'walked'.
 
         """
         pass
 
     def open_directory(self, path: str, *args) -> DirEditor:
         """Updating existing directory.
 
         """
         return DirEditor(
             self.directory,
             rootpath=self.rootpath,
             path=os.fsencode(path),
             file_states=self.file_states,
             svnrepo=self.svnrepo,
         )
 
     def add_directory(self, path: str, *args) -> DirEditor:
         """Adding a new directory.
 
         """
         path_bytes = os.fsencode(path)
         os.makedirs(os.path.join(self.rootpath, path_bytes), exist_ok=True)
         self.directory[path_bytes] = from_disk.Directory()
         return DirEditor(
             self.directory,
             rootpath=self.rootpath,
             path=path_bytes,
             file_states=self.file_states,
             svnrepo=self.svnrepo,
         )
 
     def open_file(self, *args) -> FileEditor:
         """Updating existing file.
 
         """
         path = os.fsencode(args[0])
         self.directory[path] = from_disk.Content()
         fullpath = os.path.join(self.rootpath, path)
         return FileEditor(
             self.directory,
             rootpath=self.rootpath,
             path=path,
             state=self.file_states[fullpath],
             svnrepo=self.svnrepo,
         )
 
     def add_file(self, path: str, *args) -> FileEditor:
         """Creating a new file.
 
         """
         path_bytes = os.fsencode(path)
         self.directory[path_bytes] = from_disk.Content()
         fullpath = os.path.join(self.rootpath, path_bytes)
         self.file_states[fullpath] = FileState()
         return FileEditor(
             self.directory,
             self.rootpath,
             path_bytes,
             state=self.file_states[fullpath],
             svnrepo=self.svnrepo,
         )
 
     def change_prop(self, key: str, value: str) -> None:
         """Change property callback on directory.
 
         """
         if key == properties.PROP_EXTERNALS:
+            logger.debug(
+                "Setting '%s' property with value '%s' on path %s",
+                key,
+                value,
+                self.path,
+            )
             raise ValueError("Property '%s' detected. Not implemented yet." % key)
 
     def delete_entry(self, path: str, revision: int) -> None:
         """Remove a path.
 
         """
         fullpath = os.path.join(self.rootpath, path.encode("utf-8"))
         self.file_states.pop(fullpath, None)
         self.remove_child(path.encode("utf-8"))
 
     def close(self):
         """Function called when we finish walking a repository.
 
         """
         self.update_checksum()
 
 
 class Editor:
     """Editor in charge of replaying svn events and computing objects
        along.
 
        This implementation accounts for empty folder during hash
        computations.
 
     """
 
     def __init__(
         self, rootpath: bytes, directory: from_disk.Directory, svnrepo: SvnRepo
     ):
         self.rootpath = rootpath
         self.directory = directory
         self.file_states: Dict[bytes, FileState] = {}
         self.svnrepo = svnrepo
         self.revnum = None
 
     def set_target_revision(self, revnum) -> None:
         self.revnum = revnum
 
     def abort(self) -> None:
         pass
 
     def close(self) -> None:
         pass
 
     def open_root(self, base_revnum: int) -> DirEditor:
         return DirEditor(
             self.directory,
             rootpath=self.rootpath,
             path=b"",
             file_states=self.file_states,
             svnrepo=self.svnrepo,
         )
 
 
 class Replay:
     """Replay class.
     """
 
     def __init__(
         self,
         conn: RemoteAccess,
         rootpath: bytes,
         svnrepo: SvnRepo,
         directory: Optional[from_disk.Directory] = None,
     ):
         self.conn = conn
         self.rootpath = rootpath
         if directory is None:
             directory = from_disk.Directory()
         self.directory = directory
         self.editor = Editor(rootpath=rootpath, directory=directory, svnrepo=svnrepo)
 
     def replay(self, rev: int) -> from_disk.Directory:
         """Replay svn actions between rev and rev+1.
 
         This method updates in place the self.editor.directory, as well as the
         filesystem.
 
         Returns:
            The updated root directory
 
         """
         codecs.register_error("strict", _ra_codecs_error_handler)
         self.conn.replay(rev, rev + 1, self.editor)
         codecs.register_error("strict", codecs.strict_errors)
         return self.editor.directory
 
     def compute_objects(
         self, rev: int
     ) -> Tuple[List[Content], List[SkippedContent], List[Directory]]:
         """Compute objects at revisions rev.
         Expects the state to be at previous revision's objects.
 
         Args:
             rev: The revision to start the replay from.
 
         Returns:
             The updated objects between rev and rev+1. Beware that this
             mutates the filesystem at rootpath accordingly.
 
         """
         self.replay(rev)
         return from_disk.iter_directory(self.directory)
 
 
 @click.command()
 @click.option("--local-url", default="/tmp", help="local svn working copy")
 @click.option(
     "--svn-url",
     default="file:///home/storage/svn/repos/pkg-fox",
     help="svn repository's url.",
 )
 @click.option(
     "--revision-start",
     default=1,
     type=click.INT,
     help="svn repository's starting revision.",
 )
 @click.option(
     "--revision-end",
     default=-1,
     type=click.INT,
     help="svn repository's ending revision.",
 )
 @click.option(
     "--debug/--nodebug",
     default=True,
     help="Indicates if the server should run in debug mode.",
 )
 @click.option(
     "--cleanup/--nocleanup",
     default=True,
     help="Indicates whether to cleanup disk when done or not.",
 )
 def main(local_url, svn_url, revision_start, revision_end, debug, cleanup):
     """Script to present how to use Replay class.
 
     """
     conn = RemoteAccess(svn_url.encode("utf-8"), auth=Auth([get_username_provider()]))
 
     os.makedirs(local_url, exist_ok=True)
 
     rootpath = tempfile.mkdtemp(
         prefix=local_url, suffix="-" + os.path.basename(svn_url)
     )
 
     rootpath = os.fsencode(rootpath)
 
     # Do not go beyond the repository's latest revision
     revision_end_max = conn.get_latest_revnum()
     if revision_end == -1:
         revision_end = revision_end_max
 
     revision_end = min(revision_end, revision_end_max)
 
     try:
         replay = Replay(conn, rootpath)
 
         for rev in range(revision_start, revision_end + 1):
             contents, skipped_contents, directories = replay.compute_objects(rev)
             print(
                 "r%s %s (%s new contents, %s new directories)"
                 % (
                     rev,
                     hashutil.hash_to_hex(replay.directory.hash),
                     len(contents) + len(skipped_contents),
                     len(directories),
                 )
             )
 
         if debug:
             print("%s" % rootpath.decode("utf-8"))
     finally:
         if cleanup:
             if os.path.exists(rootpath):
                 shutil.rmtree(rootpath)
 
 
 if __name__ == "__main__":
     main()