diff --git a/hscommon/.gitignore b/hscommon/.gitignore
deleted file mode 100644
index 642f9e32..00000000
--- a/hscommon/.gitignore
+++ /dev/null
@@ -1,5 +0,0 @@
-*.pyc
-*.mo
-*.so
-.DS_Store
-/docs_html
\ No newline at end of file
diff --git a/hscommon/build.py b/hscommon/build.py
index 6c37012d..bf1e4660 100644
--- a/hscommon/build.py
+++ b/hscommon/build.py
@@ -9,6 +9,7 @@
 """This module is a collection of function to help in HS apps build process.
 """
 
+from argparse import ArgumentParser
 import os
 import sys
 import os.path as op
@@ -20,18 +21,19 @@ import re
 import importlib
 from datetime import datetime
 import glob
+from typing import Any, AnyStr, Callable, Dict, List, Union
 
 from hscommon.plat import ISWINDOWS
 
 
-def print_and_do(cmd):
+def print_and_do(cmd: str) -> int:
     """Prints ``cmd`` and executes it in the shell."""
     print(cmd)
     p = Popen(cmd, shell=True)
     return p.wait()
 
 
-def _perform(src, dst, action, actionname):
+def _perform(src: os.PathLike, dst: os.PathLike, action: Callable, actionname: str) -> None:
     if not op.lexists(src):
         print("Copying %s failed: it doesn't exist." % src)
         return
@@ -44,30 +46,22 @@ def _perform(src, dst, action, actionname):
     action(src, dst)
 
 
-def copy_file_or_folder(src, dst):
+def copy_file_or_folder(src: os.PathLike, dst: os.PathLike) -> None:
     if op.isdir(src):
         shutil.copytree(src, dst, symlinks=True)
     else:
         shutil.copy(src, dst)
 
 
-def move(src, dst):
+def move(src: os.PathLike, dst: os.PathLike) -> None:
     _perform(src, dst, os.rename, "Moving")
 
 
-def copy(src, dst):
+def copy(src: os.PathLike, dst: os.PathLike) -> None:
     _perform(src, dst, copy_file_or_folder, "Copying")
 
 
-def symlink(src, dst):
-    _perform(src, dst, os.symlink, "Symlinking")
-
-
-def hardlink(src, dst):
-    _perform(src, dst, os.link, "Hardlinking")
-
-
-def _perform_on_all(pattern, dst, action):
+def _perform_on_all(pattern: AnyStr, dst: os.PathLike, action: Callable) -> None:
     # pattern is a glob pattern, example "folder/foo*". The file is moved directly in dst, no folder
     # structure from src is kept.
     filenames = glob.glob(pattern)
@@ -76,22 +70,15 @@ def _perform_on_all(pattern, dst, action):
         action(fn, destpath)
 
 
-def move_all(pattern, dst):
+def move_all(pattern: AnyStr, dst: os.PathLike) -> None:
     _perform_on_all(pattern, dst, move)
 
 
-def copy_all(pattern, dst):
+def copy_all(pattern: AnyStr, dst: os.PathLike) -> None:
     _perform_on_all(pattern, dst, copy)
 
 
-def ensure_empty_folder(path):
-    """Make sure that the path exists and that it's an empty folder."""
-    if op.exists(path):
-        shutil.rmtree(path)
-    os.mkdir(path)
-
-
-def filereplace(filename, outfilename=None, **kwargs):
+def filereplace(filename: os.PathLike, outfilename: Union[os.PathLike, None] = None, **kwargs) -> None:
     """Reads `filename`, replaces all {variables} in kwargs, and writes the result to `outfilename`."""
     if outfilename is None:
         outfilename = filename
@@ -106,12 +93,12 @@ def filereplace(filename, outfilename=None, **kwargs):
     fp.close()
 
 
-def get_module_version(modulename):
+def get_module_version(modulename: str) -> str:
     mod = importlib.import_module(modulename)
     return mod.__version__
 
 
-def setup_package_argparser(parser):
+def setup_package_argparser(parser: ArgumentParser):
     parser.add_argument(
         "--sign",
         dest="sign_identity",
@@ -138,7 +125,7 @@ def setup_package_argparser(parser):
 
 
 # `args` come from an ArgumentParser updated with setup_package_argparser()
-def package_cocoa_app_in_dmg(app_path, destfolder, args):
+def package_cocoa_app_in_dmg(app_path: os.PathLike, destfolder: os.PathLike, args) -> None:
     # Rather than signing our app in XCode during the build phase, we sign it during the package
     # phase because running the app before packaging can modify it and we want to be sure to have
     # a valid signature.
@@ -154,13 +141,14 @@ def package_cocoa_app_in_dmg(app_path, destfolder, args):
     build_dmg(app_path, destfolder)
 
 
-def build_dmg(app_path, destfolder):
+def build_dmg(app_path: os.PathLike, destfolder: os.PathLike) -> None:
     """Builds a DMG volume with application at ``app_path`` and puts it in ``dest_path``.
 
     The name of the resulting DMG volume is determined by the app's name and version.
     """
     print(repr(op.join(app_path, "Contents", "Info.plist")))
-    plist = plistlib.readPlist(op.join(app_path, "Contents", "Info.plist"))
+    with open(op.join(app_path, "Contents", "Info.plist"), "rb") as fp:
+        plist = plistlib.load(fp)
     workpath = tempfile.mkdtemp()
     dmgpath = op.join(workpath, plist["CFBundleName"])
     os.mkdir(dmgpath)
@@ -178,7 +166,7 @@ def build_dmg(app_path, destfolder):
     print("Build Complete")
 
 
-def add_to_pythonpath(path):
+def add_to_pythonpath(path: os.PathLike) -> None:
     """Adds ``path`` to both ``PYTHONPATH`` env and ``sys.path``."""
     abspath = op.abspath(path)
     pythonpath = os.environ.get("PYTHONPATH", "")
@@ -191,7 +179,12 @@ def add_to_pythonpath(path):
 # This is a method to hack around those freakingly tricky data inclusion/exlusion rules
 # in setuptools. We copy the packages *without data* in a build folder and then build the plugin
 # from there.
-def copy_packages(packages_names, dest, create_links=False, extra_ignores=None):
+def copy_packages(
+    packages_names: List[str],
+    dest: os.PathLike,
+    create_links: bool = False,
+    extra_ignores: Union[List[str], None] = None,
+) -> None:
     """Copy python packages ``packages_names`` to ``dest``, spurious data.
 
     Copy will happen without tests, testdata, mercurial data or C extension module source with it.
@@ -229,13 +222,13 @@ def copy_packages(packages_names, dest, create_links=False, extra_ignores=None):
 
 
 def build_debian_changelog(
-    changelogpath,
-    destfile,
-    pkgname,
-    from_version=None,
-    distribution="precise",
-    fix_version=None,
-):
+    changelogpath: os.PathLike,
+    destfile: os.PathLike,
+    pkgname: str,
+    from_version: Union[str, None] = None,
+    distribution: str = "precise",
+    fix_version: Union[str, None] = None,
+) -> None:
     """Builds a debian changelog out of a YAML changelog.
 
     Use fix_version to patch the top changelog to that version (if, for example, there was a
@@ -288,7 +281,7 @@ def build_debian_changelog(
 re_changelog_header = re.compile(r"=== ([\d.b]*) \(([\d\-]*)\)")
 
 
-def read_changelog_file(filename):
+def read_changelog_file(filename: os.PathLike) -> List[Dict[str, Any]]:
     def iter_by_three(it):
         while True:
             try:
@@ -315,7 +308,7 @@ def read_changelog_file(filename):
     return result
 
 
-def fix_qt_resource_file(path):
+def fix_qt_resource_file(path: os.PathLike) -> None:
     # pyrcc5 under Windows, if the locale is non-english, can produce a source file with a date
     # containing accented characters. If it does, the encoding is wrong and it prevents the file
     # from being correctly frozen by cx_freeze. To work around that, we open the file, strip all
diff --git a/hscommon/build_ext.py b/hscommon/build_ext.py
deleted file mode 100644
index db10f745..00000000
--- a/hscommon/build_ext.py
+++ /dev/null
@@ -1,30 +0,0 @@
-# Copyright 2016 Virgil Dupras
-
-# This software is licensed under the "GPLv3" License as described in the "LICENSE" file,
-# which should be included with this package. The terms are also available at
-# http://www.gnu.org/licenses/gpl-3.0.html
-
-import argparse
-
-from setuptools import setup, Extension
-
-
-def get_parser():
-    parser = argparse.ArgumentParser(description="Build an arbitrary Python extension.")
-    parser.add_argument("source_files", nargs="+", help="List of source files to compile")
-    parser.add_argument("name", nargs=1, help="Name of the resulting extension")
-    return parser
-
-
-def main():
-    args = get_parser().parse_args()
-    print(f"Building {args.name[0]}...")
-    ext = Extension(args.name[0], args.source_files)
-    setup(
-        script_args=["build_ext", "--inplace"],
-        ext_modules=[ext],
-    )
-
-
-if __name__ == "__main__":
-    main()
diff --git a/hscommon/conflict.py b/hscommon/conflict.py
index 970ad1df..af133ac7 100644
--- a/hscommon/conflict.py
+++ b/hscommon/conflict.py
@@ -15,6 +15,7 @@ import os
 import shutil
 
 from pathlib import Path
+from typing import Callable, List
 
 # This matches [123], but not [12] (3 digits being the minimum).
 # It also matches [1234] [12345] etc..
@@ -22,7 +23,7 @@ from pathlib import Path
 re_conflict = re.compile(r"^\[\d{3}\d*\] ")
 
 
-def get_conflicted_name(other_names, name):
+def get_conflicted_name(other_names: List[str], name: str) -> str:
     """Returns name with a ``[000]`` number in front of it.
 
     The number between brackets depends on how many conlicted filenames
@@ -39,7 +40,7 @@ def get_conflicted_name(other_names, name):
         i += 1
 
 
-def get_unconflicted_name(name):
+def get_unconflicted_name(name: str) -> str:
     """Returns ``name`` without ``[]`` brackets.
 
     Brackets which, of course, might have been added by func:`get_conflicted_name`.
@@ -47,12 +48,12 @@ def get_unconflicted_name(name):
     return re_conflict.sub("", name, 1)
 
 
-def is_conflicted(name):
+def is_conflicted(name: str) -> bool:
     """Returns whether ``name`` is prepended with a bracketed number."""
     return re_conflict.match(name) is not None
 
 
-def _smart_move_or_copy(operation, source_path: Path, dest_path: Path):
+def _smart_move_or_copy(operation: Callable, source_path: Path, dest_path: Path) -> None:
     """Use move() or copy() to move and copy file with the conflict management."""
     if dest_path.is_dir() and not source_path.is_dir():
         dest_path = dest_path.joinpath(source_path.name)
@@ -64,12 +65,12 @@ def _smart_move_or_copy(operation, source_path: Path, dest_path: Path):
     operation(str(source_path), str(dest_path))
 
 
-def smart_move(source_path, dest_path):
+def smart_move(source_path: Path, dest_path: Path) -> None:
     """Same as :func:`smart_copy`, but it moves files instead."""
     _smart_move_or_copy(shutil.move, source_path, dest_path)
 
 
-def smart_copy(source_path, dest_path):
+def smart_copy(source_path: Path, dest_path: Path) -> None:
     """Copies ``source_path`` to ``dest_path``, recursively and with conflict resolution."""
     try:
         _smart_move_or_copy(shutil.copy, source_path, dest_path)
diff --git a/hscommon/loc.py b/hscommon/loc.py
index a435fc8e..c185aa6e 100644
--- a/hscommon/loc.py
+++ b/hscommon/loc.py
@@ -2,6 +2,7 @@ import os
 import os.path as op
 import shutil
 import tempfile
+from typing import Any, List
 
 import polib
 
@@ -10,15 +11,15 @@ from hscommon import pygettext
 LC_MESSAGES = "LC_MESSAGES"
 
 
-def get_langs(folder):
+def get_langs(folder: str) -> List[str]:
     return [name for name in os.listdir(folder) if op.isdir(op.join(folder, name))]
 
 
-def files_with_ext(folder, ext):
+def files_with_ext(folder: str, ext: str) -> List[str]:
     return [op.join(folder, fn) for fn in os.listdir(folder) if fn.endswith(ext)]
 
 
-def generate_pot(folders, outpath, keywords, merge=False):
+def generate_pot(folders: List[str], outpath: str, keywords: Any, merge: bool = False) -> None:
     if merge and not op.exists(outpath):
         merge = False
     if merge:
@@ -39,7 +40,7 @@ def generate_pot(folders, outpath, keywords, merge=False):
             print("Exception while removing temporary folder %s\n", genpath)
 
 
-def compile_all_po(base_folder):
+def compile_all_po(base_folder: str) -> None:
     langs = get_langs(base_folder)
     for lang in langs:
         pofolder = op.join(base_folder, lang, LC_MESSAGES)
@@ -49,7 +50,7 @@ def compile_all_po(base_folder):
             p.save_as_mofile(pofile[:-3] + ".mo")
 
 
-def merge_locale_dir(target, mergeinto):
+def merge_locale_dir(target: str, mergeinto: str) -> None:
     langs = get_langs(target)
     for lang in langs:
         if not op.exists(op.join(mergeinto, lang)):
@@ -60,7 +61,7 @@ def merge_locale_dir(target, mergeinto):
             shutil.copy(mofile, op.join(mergeinto, lang, LC_MESSAGES))
 
 
-def merge_pots_into_pos(folder):
+def merge_pots_into_pos(folder: str) -> None:
     # We're going to take all pot files in `folder` and for each lang, merge it with the po file
     # with the same name.
     potfiles = files_with_ext(folder, ".pot")
@@ -73,7 +74,7 @@ def merge_pots_into_pos(folder):
             po.save()
 
 
-def merge_po_and_preserve(source, dest):
+def merge_po_and_preserve(source: str, dest: str) -> None:
     # Merges source entries into dest, but keep old entries intact
     sourcepo = polib.pofile(source)
     destpo = polib.pofile(dest)
@@ -85,7 +86,7 @@ def merge_po_and_preserve(source, dest):
     destpo.save()
 
 
-def normalize_all_pos(base_folder):
+def normalize_all_pos(base_folder: str) -> None:
     """Normalize the format of .po files in base_folder.
 
     When getting POs from external sources, such as Transifex, we end up with spurious diffs because
diff --git a/hscommon/notify.py b/hscommon/notify.py
index d5d55c89..71c28481 100644
--- a/hscommon/notify.py
+++ b/hscommon/notify.py
@@ -13,6 +13,7 @@ the method with the same name as the broadcasted message is called on the listen
 """
 
 from collections import defaultdict
+from typing import Callable, DefaultDict, List
 
 
 class Broadcaster:
@@ -21,10 +22,10 @@ class Broadcaster:
     def __init__(self):
         self.listeners = set()
 
-    def add_listener(self, listener):
+    def add_listener(self, listener: "Listener") -> None:
         self.listeners.add(listener)
 
-    def notify(self, msg):
+    def notify(self, msg: str) -> None:
         """Notify all connected listeners of ``msg``.
 
         That means that each listeners will have their method with the same name as ``msg`` called.
@@ -33,18 +34,18 @@ class Broadcaster:
             if listener in self.listeners:  # disconnected during notification
                 listener.dispatch(msg)
 
-    def remove_listener(self, listener):
+    def remove_listener(self, listener: "Listener") -> None:
         self.listeners.discard(listener)
 
 
 class Listener:
     """A listener is initialized with the broadcaster it's going to listen to. Initially, it is not connected."""
 
-    def __init__(self, broadcaster):
+    def __init__(self, broadcaster: Broadcaster) -> None:
         self.broadcaster = broadcaster
-        self._bound_notifications = defaultdict(list)
+        self._bound_notifications: DefaultDict[str, List[Callable]] = defaultdict(list)
 
-    def bind_messages(self, messages, func):
+    def bind_messages(self, messages: str, func: Callable) -> None:
         """Binds multiple message to the same function.
 
         Often, we perform the same thing on multiple messages. Instead of having the same function
@@ -54,15 +55,15 @@ class Listener:
         for message in messages:
             self._bound_notifications[message].append(func)
 
-    def connect(self):
+    def connect(self) -> None:
         """Connects the listener to its broadcaster."""
         self.broadcaster.add_listener(self)
 
-    def disconnect(self):
+    def disconnect(self) -> None:
         """Disconnects the listener from its broadcaster."""
         self.broadcaster.remove_listener(self)
 
-    def dispatch(self, msg):
+    def dispatch(self, msg: str) -> None:
         if msg in self._bound_notifications:
             for func in self._bound_notifications[msg]:
                 func()
@@ -74,14 +75,14 @@ class Listener:
 class Repeater(Broadcaster, Listener):
     REPEATED_NOTIFICATIONS = None
 
-    def __init__(self, broadcaster):
+    def __init__(self, broadcaster: Broadcaster) -> None:
         Broadcaster.__init__(self)
         Listener.__init__(self, broadcaster)
 
-    def _repeat_message(self, msg):
+    def _repeat_message(self, msg: str) -> None:
         if not self.REPEATED_NOTIFICATIONS or msg in self.REPEATED_NOTIFICATIONS:
             self.notify(msg)
 
-    def dispatch(self, msg):
+    def dispatch(self, msg: str) -> None:
         Listener.dispatch(self, msg)
         self._repeat_message(msg)
diff --git a/hscommon/sphinxgen.py b/hscommon/sphinxgen.py
index 52c9ea8e..c4e4958b 100644
--- a/hscommon/sphinxgen.py
+++ b/hscommon/sphinxgen.py
@@ -6,6 +6,7 @@
 
 from pathlib import Path
 import re
+from typing import Callable, Dict, Union
 
 from hscommon.build import read_changelog_file, filereplace
 from sphinx.cmd.build import build_main as sphinx_build
@@ -18,7 +19,7 @@ CHANGELOG_FORMAT = """
 """
 
 
-def tixgen(tixurl):
+def tixgen(tixurl: str) -> Callable[[str], str]:
     """This is a filter *generator*. tixurl is a url pattern for the tix with a {0} placeholder
     for the tix #
     """
@@ -29,14 +30,14 @@ def tixgen(tixurl):
 
 
 def gen(
-    basepath,
-    destpath,
-    changelogpath,
-    tixurl,
-    confrepl=None,
-    confpath=None,
-    changelogtmpl=None,
-):
+    basepath: Path,
+    destpath: Path,
+    changelogpath: Path,
+    tixurl: str,
+    confrepl: Union[Dict[str, str], None] = None,
+    confpath: Union[Path, None] = None,
+    changelogtmpl: Union[Path, None] = None,
+) -> None:
     """Generate sphinx docs with all bells and whistles.
 
     basepath: The base sphinx source path.
diff --git a/hscommon/sqlite.py b/hscommon/sqlite.py
deleted file mode 100644
index 686ef5ab..00000000
--- a/hscommon/sqlite.py
+++ /dev/null
@@ -1,141 +0,0 @@
-# Created By: Virgil Dupras
-# Created On: 2007/05/19
-# Copyright 2015 Hardcoded Software (http://www.hardcoded.net)
-
-# This software is licensed under the "GPLv3" License as described in the "LICENSE" file,
-# which should be included with this package. The terms are also available at
-# http://www.gnu.org/licenses/gpl-3.0.html
-
-import os
-import os.path as op
-import threading
-from queue import Queue
-import sqlite3 as sqlite
-
-STOP = object()
-COMMIT = object()
-ROLLBACK = object()
-
-
-class FakeCursor(list):
-    # It's not possible to use sqlite cursors on another thread than the connection. Thus,
-    # we can't directly return the cursor. We have to fatch all results, and support its interface.
-    def fetchall(self):
-        return self
-
-    def fetchone(self):
-        try:
-            return self.pop(0)
-        except IndexError:
-            return None
-
-
-class _ActualThread(threading.Thread):
-    """We can't use this class directly because thread object are not automatically freed when
-    nothing refers to it, making it hang the application if not explicitely closed.
-    """
-
-    def __init__(self, dbname, autocommit):
-        threading.Thread.__init__(self)
-        self._queries = Queue()
-        self._results = Queue()
-        self._dbname = dbname
-        self._autocommit = autocommit
-        self._waiting_list = set()
-        self._lock = threading.Lock()
-        self._run = True
-        self.lastrowid = -1
-        self.daemon = True
-        self.start()
-
-    def _query(self, query):
-        with self._lock:
-            wait_token = object()
-            self._waiting_list.add(wait_token)
-            self._queries.put(query)
-            self._waiting_list.remove(wait_token)
-            result = self._results.get()
-        return result
-
-    def close(self):
-        if not self._run:
-            return
-        self._query(STOP)
-
-    def commit(self):
-        if not self._run:
-            return None  # Connection closed
-        self._query(COMMIT)
-
-    def execute(self, sql, values=()):
-        if not self._run:
-            return None  # Connection closed
-        result = self._query((sql, values))
-        if isinstance(result, Exception):
-            raise result
-        return result
-
-    def rollback(self):
-        if not self._run:
-            return None  # Connection closed
-        self._query(ROLLBACK)
-
-    def run(self):
-        # The whole chdir thing is because sqlite doesn't handle directory names with non-asci char in the AT ALL.
-        oldpath = os.getcwd()
-        dbdir, dbname = op.split(self._dbname)
-        if dbdir:
-            os.chdir(dbdir)
-        if self._autocommit:
-            con = sqlite.connect(dbname, isolation_level=None)
-        else:
-            con = sqlite.connect(dbname)
-        os.chdir(oldpath)
-        while self._run or self._waiting_list:
-            query = self._queries.get()
-            result = None
-            if query is STOP:
-                self._run = False
-            elif query is COMMIT:
-                con.commit()
-            elif query is ROLLBACK:
-                con.rollback()
-            else:
-                sql, values = query
-                try:
-                    cur = con.execute(sql, values)
-                    self.lastrowid = cur.lastrowid
-                    result = FakeCursor(cur.fetchall())
-                    result.lastrowid = cur.lastrowid
-                except Exception as e:
-                    result = e
-            self._results.put(result)
-        con.close()
-
-
-class ThreadedConn:
-    """``sqlite`` connections can't be used across threads. ``TheadedConn`` opens a sqlite
-    connection in its own thread and sends it queries through a queue, making it suitable in
-    multi-threaded environment.
-    """
-
-    def __init__(self, dbname, autocommit):
-        self._t = _ActualThread(dbname, autocommit)
-        self.lastrowid = -1
-
-    def __del__(self):
-        self.close()
-
-    def close(self):
-        self._t.close()
-
-    def commit(self):
-        self._t.commit()
-
-    def execute(self, sql, values=()):
-        result = self._t.execute(sql, values)
-        self.lastrowid = self._t.lastrowid
-        return result
-
-    def rollback(self):
-        self._t.rollback()
diff --git a/hscommon/tests/sqlite_test.py b/hscommon/tests/sqlite_test.py
deleted file mode 100644
index 88afe60c..00000000
--- a/hscommon/tests/sqlite_test.py
+++ /dev/null
@@ -1,137 +0,0 @@
-# Created By: Virgil Dupras
-# Created On: 2007/05/19
-# Copyright 2015 Hardcoded Software (http://www.hardcoded.net)
-
-# This software is licensed under the "GPLv3" License as described in the "LICENSE" file,
-# which should be included with this package. The terms are also available at
-# http://www.gnu.org/licenses/gpl-3.0.html
-
-import time
-import threading
-import os
-import sqlite3 as sqlite
-
-from pytest import raises
-
-from hscommon.testutil import eq_
-from hscommon.sqlite import ThreadedConn
-
-# Threading is hard to test. In a lot of those tests, a failure means that the test run will
-# hang forever. Well... I don't know a better alternative.
-
-
-def test_can_access_from_multiple_threads():
-    def run():
-        con.execute("insert into foo(bar) values('baz')")
-
-    con = ThreadedConn(":memory:", True)
-    con.execute("create table foo(bar TEXT)")
-    t = threading.Thread(target=run)
-    t.start()
-    t.join()
-    result = con.execute("select * from foo")
-    eq_(1, len(result))
-    eq_("baz", result[0][0])
-
-
-def test_exception_during_query():
-    con = ThreadedConn(":memory:", True)
-    con.execute("create table foo(bar TEXT)")
-    with raises(sqlite.OperationalError):
-        con.execute("select * from bleh")
-
-
-def test_not_autocommit(tmpdir):
-    dbpath = str(tmpdir.join("foo.db"))
-    con = ThreadedConn(dbpath, False)
-    con.execute("create table foo(bar TEXT)")
-    con.execute("insert into foo(bar) values('baz')")
-    del con
-    # The data shouldn't have been inserted
-    con = ThreadedConn(dbpath, False)
-    result = con.execute("select * from foo")
-    eq_(0, len(result))
-    con.execute("insert into foo(bar) values('baz')")
-    con.commit()
-    del con
-    # Now the data should be there
-    con = ThreadedConn(dbpath, False)
-    result = con.execute("select * from foo")
-    eq_(1, len(result))
-
-
-def test_rollback():
-    con = ThreadedConn(":memory:", False)
-    con.execute("create table foo(bar TEXT)")
-    con.execute("insert into foo(bar) values('baz')")
-    con.rollback()
-    result = con.execute("select * from foo")
-    eq_(0, len(result))
-
-
-def test_query_palceholders():
-    con = ThreadedConn(":memory:", True)
-    con.execute("create table foo(bar TEXT)")
-    con.execute("insert into foo(bar) values(?)", ["baz"])
-    result = con.execute("select * from foo")
-    eq_(1, len(result))
-    eq_("baz", result[0][0])
-
-
-def test_make_sure_theres_no_messup_between_queries():
-    def run(expected_rowid):
-        time.sleep(0.1)
-        result = con.execute("select rowid from foo where rowid = ?", [expected_rowid])
-        assert expected_rowid == result[0][0]
-
-    con = ThreadedConn(":memory:", True)
-    con.execute("create table foo(bar TEXT)")
-    for i in range(100):
-        con.execute("insert into foo(bar) values('baz')")
-    threads = []
-    for i in range(1, 101):
-        t = threading.Thread(target=run, args=(i,))
-        t.start()
-        threads.append(t)
-    while threads:
-        time.sleep(0.1)
-        threads = [t for t in threads if t.is_alive()]
-
-
-def test_query_after_close():
-    con = ThreadedConn(":memory:", True)
-    con.close()
-    con.execute("select 1")
-
-
-def test_lastrowid():
-    # It's not possible to return a cursor because of the threading, but lastrowid should be
-    # fetchable from the connection itself
-    con = ThreadedConn(":memory:", True)
-    con.execute("create table foo(bar TEXT)")
-    con.execute("insert into foo(bar) values('baz')")
-    eq_(1, con.lastrowid)
-
-
-def test_add_fetchone_fetchall_interface_to_results():
-    con = ThreadedConn(":memory:", True)
-    con.execute("create table foo(bar TEXT)")
-    con.execute("insert into foo(bar) values('baz1')")
-    con.execute("insert into foo(bar) values('baz2')")
-    result = con.execute("select * from foo")
-    ref = result[:]
-    eq_(ref, result.fetchall())
-    eq_(ref[0], result.fetchone())
-    eq_(ref[1], result.fetchone())
-    assert result.fetchone() is None
-
-
-def test_non_ascii_dbname(tmpdir):
-    ThreadedConn(str(tmpdir.join("foo\u00e9.db")), True)
-
-
-def test_non_ascii_dbdir(tmpdir):
-    # when this test fails, it doesn't fail gracefully, it brings the whole test suite with it.
-    dbdir = tmpdir.join("foo\u00e9")
-    os.mkdir(str(dbdir))
-    ThreadedConn(str(dbdir.join("foo.db")), True)
diff --git a/hscommon/trans.py b/hscommon/trans.py
index fa32510c..86628831 100644
--- a/hscommon/trans.py
+++ b/hscommon/trans.py
@@ -11,7 +11,9 @@
 
 import locale
 import logging
+import os
 import os.path as op
+from typing import Callable, Union
 
 from hscommon.plat import ISLINUX
 
@@ -20,7 +22,7 @@ _trget = None
 installed_lang = None
 
 
-def tr(s, context=None):
+def tr(s: str, context: Union[str, None] = None) -> str:
     if _trfunc is None:
         return s
     else:
@@ -30,7 +32,7 @@ def tr(s, context=None):
             return _trfunc(s)
 
 
-def trget(domain):
+def trget(domain: str) -> Callable[[str], str]:
     # Returns a tr() function for the specified domain.
     if _trget is None:
         return lambda s: tr(s, domain)
@@ -38,14 +40,16 @@ def trget(domain):
         return _trget(domain)
 
 
-def set_tr(new_tr, new_trget=None):
+def set_tr(
+    new_tr: Callable[[str, Union[str, None]], str], new_trget: Union[Callable[[str], Callable[[str], str]], None] = None
+) -> None:
     global _trfunc, _trget
     _trfunc = new_tr
     if new_trget is not None:
         _trget = new_trget
 
 
-def get_locale_name(lang):
+def get_locale_name(lang: str) -> Union[str, None]:
     # Removed old conversion code as windows seems to support these
     LANG2LOCALENAME = {
         "cs": "cs_CZ",
@@ -77,7 +81,7 @@ def get_locale_name(lang):
 
 
 # --- Qt
-def install_qt_trans(lang=None):
+def install_qt_trans(lang: str = None) -> None:
     from PyQt5.QtCore import QCoreApplication, QTranslator, QLocale
 
     if not lang:
@@ -97,17 +101,19 @@ def install_qt_trans(lang=None):
     qtr2.load(":/%s" % lang)
     QCoreApplication.installTranslator(qtr2)
 
-    def qt_tr(s, context="core"):
+    def qt_tr(s: str, context: Union[str, None] = "core") -> str:
+        if context is None:
+            context = "core"
         return str(QCoreApplication.translate(context, s, None))
 
     set_tr(qt_tr)
 
 
 # --- gettext
-def install_gettext_trans(base_folder, lang):
+def install_gettext_trans(base_folder: os.PathLike, lang: str) -> None:
     import gettext
 
-    def gettext_trget(domain):
+    def gettext_trget(domain: str) -> Callable[[str], str]:
         if not lang:
             return lambda s: s
         try:
@@ -117,7 +123,7 @@ def install_gettext_trans(base_folder, lang):
 
     default_gettext = gettext_trget("core")
 
-    def gettext_tr(s, context=None):
+    def gettext_tr(s: str, context: Union[str, None] = None) -> str:
         if not context:
             return default_gettext(s)
         else:
@@ -129,7 +135,7 @@ def install_gettext_trans(base_folder, lang):
     installed_lang = lang
 
 
-def install_gettext_trans_under_qt(base_folder, lang=None):
+def install_gettext_trans_under_qt(base_folder: os.PathLike, lang: str = None) -> None:
     # So, we install the gettext locale, great, but we also should try to install qt_*.qm if
     # available so that strings that are inside Qt itself over which I have no control are in the
     # right language.