diff --git a/odoo/http.py b/odoo/http.py
index 1484b78b791..222a2eeabb4 100644
--- a/odoo/http.py
+++ b/odoo/http.py
@@ -5,6 +5,7 @@
 import ast
 import collections
 import contextlib
+import copy
 import datetime
 import functools
 import hashlib
@@ -305,8 +306,15 @@ class WebRequest(object):
                 and not isinstance(exception, werkzeug.exceptions.HTTPException):
             odoo.tools.debugger.post_mortem(
                 odoo.tools.config, sys.exc_info())
-        # otherwise "no active exception to reraise"
-        raise pycompat.reraise(type(exception), exception, sys.exc_info()[2])
+
+        # WARNING: do not inline or it breaks: raise...from evaluates strictly
+        # LTR so would first remove traceback then copy lack of traceback
+        new_cause = Exception().with_traceback(exception.__traceback__)
+        # tries to provide good chained tracebacks, just re-raising exception
+        # generates a weird message as stacks just get concatenated, exceptions
+        # not guaranteed to copy.copy cleanly & we want `exception` as leaf (for
+        # callers to check & look at)
+        raise exception.with_traceback(None) from new_cause
 
     def _call_function(self, *args, **kwargs):
         request = self
diff --git a/odoo/tools/convert.py b/odoo/tools/convert.py
index 4fd29e57417..d41b33a360a 100644
--- a/odoo/tools/convert.py
+++ b/odoo/tools/convert.py
@@ -712,15 +712,7 @@ form: module.record_id""" % (xml_id,)
         try:
             self._tag_root(de)
         except Exception as e:
-            exc_info = sys.exc_info()
-            pycompat.reraise(
-                ParseError,
-                ParseError(
-                    ustr(e),
-                    etree.tostring(de, encoding='unicode').rstrip(),
-                    de.getroottree().docinfo.URL, de.sourceline),
-                exc_info[2]
-            )
+            raise ParseError(ustr(e), etree.tostring(de, encoding='unicode').rstrip(), de.getroottree().docinfo.URL, de.sourceline)
     DATA_ROOTS = ['odoo', 'data', 'openerp']
 
 def convert_file(cr, module, filename, idref, mode='update', noupdate=False, kind=None, report=None, pathname=None):
diff --git a/odoo/tools/pycompat.py b/odoo/tools/pycompat.py
index d13e706b934..81e41829ae2 100644
--- a/odoo/tools/pycompat.py
+++ b/odoo/tools/pycompat.py
@@ -1,19 +1,9 @@
 # -*- coding: utf-8 -*-
-# to remove if we decide to add a dependency on six or future
-# very strongly inspired by https://github.com/pallets/werkzeug/blob/master/werkzeug/_compat.py
 #pylint: disable=deprecated-module
 import csv
 import codecs
-import collections
 import io
 
-
-def reraise(tp, value, tb=None):
-    if value.__traceback__ != tb:
-        raise value.with_traceback(tb)
-    raise value
-
-
 _reader = codecs.getreader('utf-8')
 _writer = codecs.getwriter('utf-8')
 
diff --git a/odoo/tools/safe_eval.py b/odoo/tools/safe_eval.py
index 813fd822e39..060514fbf91 100644
--- a/odoo/tools/safe_eval.py
+++ b/odoo/tools/safe_eval.py
@@ -207,8 +207,7 @@ def test_expr(expr, allowed_codes, mode="eval"):
     except (SyntaxError, TypeError, ValueError):
         raise
     except Exception as e:
-        exc_info = sys.exc_info()
-        pycompat.reraise(ValueError, ValueError('"%s" while compiling\n%r' % (ustr(e), expr)), exc_info[2])
+        raise ValueError('"%s" while compiling\n%r' % (ustr(e), expr))
     assert_valid_codeobj(allowed_codes, code_obj, expr)
     return code_obj
 
@@ -368,8 +367,7 @@ def safe_eval(expr, globals_dict=None, locals_dict=None, mode="eval", nocopy=Fal
     except odoo.exceptions.MissingError:
         raise
     except Exception as e:
-        exc_info = sys.exc_info()
-        pycompat.reraise(ValueError, ValueError('%s: "%s" while evaluating\n%r' % (ustr(type(e)), ustr(e), expr)), exc_info[2])
+        raise ValueError('%s: "%s" while evaluating\n%r' % (ustr(type(e)), ustr(e), expr))
 def test_python_expr(expr, mode="eval"):
     try:
         test_expr(expr, _SAFE_OPCODES, mode=mode)