diff --git a/tests/Readme.md b/tests/Readme.md
index f8dd91db0..668552c94 100644
--- a/tests/Readme.md
+++ b/tests/Readme.md
@@ -30,6 +30,11 @@ Specify path to pg_probackup binary file. By default tests use <Path to Git repo
 Remote backup depends on key authentication to local machine via ssh as current user.
  export PGPROBACKUP_SSH_REMOTE=ON
 
+Run tests that are relied on advanced debugging features. For this mode, pg_probackup should be compiled without optimizations. For example:
+CFLAGS="-O0" ./configure --prefix=/path/to/prefix --enable-debug --enable-cassert --enable-depend --enable-tap-tests
+
+ export PGPROBACKUP_GDB=ON
+
 Run suit of basic simple tests:
  export PG_PROBACKUP_TEST_BASIC=ON
 
diff --git a/tests/archive.py b/tests/archive.py
index 44fd7bcfb..0ade2d66a 100644
--- a/tests/archive.py
+++ b/tests/archive.py
@@ -1547,8 +1547,8 @@ def test_archive_catalog_1(self):
         double segment - compressed and not
         """
         if not self.archive_compress:
-            return self.fail(
-                'You need to enable ARCHIVE_COMPRESSION for this test to run')
+            self.skipTest('You need to enable ARCHIVE_COMPRESSION '
+                          'for this test to run')
 
         fname = self.id().split('.')[3]
         backup_dir = os.path.join(self.tmp_path, module_name, fname, 'backup')
@@ -1602,8 +1602,8 @@ def test_archive_catalog_2(self):
         double segment - compressed and not
         """
         if not self.archive_compress:
-            return self.fail(
-                'You need to enable ARCHIVE_COMPRESSION for this test to run')
+            self.skipTest('You need to enable ARCHIVE_COMPRESSION '
+                          'for this test to run')
 
         fname = self.id().split('.')[3]
         backup_dir = os.path.join(self.tmp_path, module_name, fname, 'backup')
@@ -1659,6 +1659,9 @@ def test_archive_options(self):
         check that '--archive-host', '--archive-user', '--archiver-port'
         and '--restore-command' are working as expected.
         """
+        if not self.remote:
+            self.skipTest("You must enable PGPROBACKUP_SSH_REMOTE"
+                          " for run this test")
         fname = self.id().split('.')[3]
         backup_dir = os.path.join(self.tmp_path, module_name, fname, 'backup')
         node = self.make_simple_node(
diff --git a/tests/checkdb.py b/tests/checkdb.py
index 5b7a156cc..aecd4bde1 100644
--- a/tests/checkdb.py
+++ b/tests/checkdb.py
@@ -450,6 +450,11 @@ def test_checkdb_block_validation_sanity(self):
     # @unittest.skip("skip")
     def test_checkdb_sigint_handling(self):
         """"""
+        if not self.gdb:
+            self.skipTest(
+                "Specify PGPROBACKUP_GDB and build without "
+                "optimizations for run this test"
+            )
         fname = self.id().split('.')[3]
         backup_dir = os.path.join(self.tmp_path, module_name, fname, 'backup')
         node = self.make_simple_node(
diff --git a/tests/delta.py b/tests/delta.py
index c2f58d10f..f365b6f9b 100644
--- a/tests/delta.py
+++ b/tests/delta.py
@@ -472,6 +472,11 @@ def test_delta_vacuum_full(self):
         make node, make full and delta stream backups,
         restore them and check data correctness
         """
+        if not self.gdb:
+            self.skipTest(
+                "Specify PGPROBACKUP_GDB and build without "
+                "optimizations for run this test"
+            )
         fname = self.id().split('.')[3]
         backup_dir = os.path.join(self.tmp_path, module_name, fname, 'backup')
         node = self.make_simple_node(
@@ -508,7 +513,7 @@ def test_delta_vacuum_full(self):
         process.start()
 
         while not gdb.stopped_in_breakpoint:
-            sleep(1)
+            time.sleep(1)
 
         gdb.continue_execution_until_break(20)
 
diff --git a/tests/external.py b/tests/external.py
index 5c970f57b..530e7fb26 100644
--- a/tests/external.py
+++ b/tests/external.py
@@ -373,6 +373,9 @@ def test_external_backward_compatibility(self):
         restore delta backup, check that incremental chain
         restored correctly
         """
+        if not self.probackup_old_path:
+            self.skipTest("You must specify PGPROBACKUPBIN_OLD"
+                          " for run this test")
         fname = self.id().split('.')[3]
         backup_dir = os.path.join(self.tmp_path, module_name, fname, 'backup')
         node = self.make_simple_node(
@@ -474,6 +477,9 @@ def test_external_backward_compatibility_merge_1(self):
         take delta backup with new binary and 2 external directories
         merge delta backup ajd restore it
         """
+        if not self.probackup_old_path:
+            self.skipTest("You must specify PGPROBACKUPBIN_OLD"
+                          " for run this test")
         fname = self.id().split('.')[3]
         backup_dir = os.path.join(self.tmp_path, module_name, fname, 'backup')
         node = self.make_simple_node(
@@ -566,6 +572,9 @@ def test_external_backward_compatibility_merge_2(self):
         take delta backup with new binary and 2 external directories
         merge delta backup and restore it
         """
+        if not self.probackup_old_path:
+            self.skipTest("You must specify PGPROBACKUPBIN_OLD"
+                          " for run this test")
         fname = self.id().split('.')[3]
         backup_dir = os.path.join(self.tmp_path, module_name, fname, 'backup')
         node = self.make_simple_node(
@@ -687,6 +696,9 @@ def test_external_backward_compatibility_merge_2(self):
     # @unittest.skip("skip")
     def test_external_merge(self):
         """"""
+        if not self.probackup_old_path:
+            self.skipTest("You must specify PGPROBACKUPBIN_OLD"
+                          " for run this test")
         fname = self.id().split('.')[3]
         backup_dir = os.path.join(self.tmp_path, module_name, fname, 'backup')
         node = self.make_simple_node(
diff --git a/tests/helpers/ptrack_helpers.py b/tests/helpers/ptrack_helpers.py
index bf84f266e..1f630af3b 100644
--- a/tests/helpers/ptrack_helpers.py
+++ b/tests/helpers/ptrack_helpers.py
@@ -184,15 +184,15 @@ def __init__(self, *args, **kwargs):
         self.test_env['LC_MESSAGES'] = 'C'
         self.test_env['LC_TIME'] = 'C'
 
-        self.paranoia = False
-        if 'PG_PROBACKUP_PARANOIA' in self.test_env:
-            if self.test_env['PG_PROBACKUP_PARANOIA'] == 'ON':
-                self.paranoia = True
-
-        self.archive_compress = False
-        if 'ARCHIVE_COMPRESSION' in self.test_env:
-            if self.test_env['ARCHIVE_COMPRESSION'] == 'ON':
-                self.archive_compress = True
+        self.gdb = 'PGPROBACKUP_GDB' in os.environ and \
+              os.environ['PGPROBACKUP_GDB'] == 'ON'
+
+        self.paranoia = 'PG_PROBACKUP_PARANOIA' in self.test_env and \
+            self.test_env['PG_PROBACKUP_PARANOIA'] == 'ON'
+
+        self.archive_compress = 'ARCHIVE_COMPRESSION' in self.test_env and \
+            self.test_env['ARCHIVE_COMPRESSION'] == 'ON'
+
         try:
             testgres.configure_testgres(
                 cache_initdb=False,
diff --git a/tests/pgpro2068.py b/tests/pgpro2068.py
index e373a84b8..fc0cb50bd 100644
--- a/tests/pgpro2068.py
+++ b/tests/pgpro2068.py
@@ -18,6 +18,11 @@ def test_minrecpoint_on_replica(self):
         """
         https://jira.postgrespro.ru/browse/PGPRO-2068
         """
+        if not self.gdb:
+            self.skipTest(
+                "Specify PGPROBACKUP_GDB and build without "
+                "optimizations for run this test"
+            )
         fname = self.id().split('.')[3]
         node = self.make_simple_node(
             base_dir=os.path.join(module_name, fname, 'node'),
diff --git a/tests/replica.py b/tests/replica.py
index d59b11dbf..828305da7 100644
--- a/tests/replica.py
+++ b/tests/replica.py
@@ -625,6 +625,11 @@ def test_replica_promote(self):
     def test_replica_stop_lsn_null_offset(self):
         """
         """
+        if not self.gdb:
+            self.skipTest(
+                "Specify PGPROBACKUP_GDB and build without "
+                "optimizations for run this test"
+            )
         fname = self.id().split('.')[3]
         backup_dir = os.path.join(self.tmp_path, module_name, fname, 'backup')
         master = self.make_simple_node(
@@ -707,6 +712,11 @@ def test_replica_stop_lsn_null_offset(self):
     def test_replica_stop_lsn_null_offset_next_record(self):
         """
         """
+        if not self.gdb:
+            self.skipTest(
+                "Specify PGPROBACKUP_GDB and build without "
+                "optimizations for run this test"
+            )
         fname = self.id().split('.')[3]
         backup_dir = os.path.join(self.tmp_path, module_name, fname, 'backup')
         master = self.make_simple_node(
@@ -976,6 +986,11 @@ def test_replica_toast(self):
         make archive master, take full and page archive backups from master,
         set replica, make archive backup from replica
         """
+        if not self.gdb:
+            self.skipTest(
+                "Specify PGPROBACKUP_GDB and build without "
+                "optimizations for run this test"
+            )
         fname = self.id().split('.')[3]
         backup_dir = os.path.join(self.tmp_path, module_name, fname, 'backup')
         master = self.make_simple_node(
@@ -1076,6 +1091,11 @@ def test_replica_toast(self):
     def test_start_stop_lsn_in_the_same_segno(self):
         """
         """
+        if not self.gdb:
+            self.skipTest(
+                "Specify PGPROBACKUP_GDB and build without "
+                "optimizations for run this test"
+            )
         fname = self.id().split('.')[3]
         backup_dir = os.path.join(self.tmp_path, module_name, fname, 'backup')
         master = self.make_simple_node(
diff --git a/tests/restore.py b/tests/restore.py
index 8ccffa44c..d0353d05f 100644
--- a/tests/restore.py
+++ b/tests/restore.py
@@ -189,7 +189,7 @@ def test_restore_to_time(self):
         node = self.make_simple_node(
             base_dir=os.path.join(module_name, fname, 'node'),
             initdb_params=['--data-checksums'],
-            pg_options={'TimeZone': 'Europe/Moscow'})
+            pg_options={'TimeZone': 'GMT'})
 
         backup_dir = os.path.join(self.tmp_path, module_name, fname, 'backup')
         self.init_pb(backup_dir)
@@ -202,7 +202,9 @@ def test_restore_to_time(self):
 
         backup_id = self.backup_node(backup_dir, 'node', node)
 
-        target_time = datetime.now().strftime("%Y-%m-%d %H:%M:%S")
+        target_time = node.execute(
+            "postgres", "SELECT to_char(now(), 'YYYY-MM-DD HH24:MI:SS+00')"
+        )[0][0]
         pgbench = node.pgbench(
             stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
         pgbench.wait()
@@ -2848,6 +2850,9 @@ def test_partial_restore_backward_compatibility_1(self):
         """
         old binary should be of version < 2.2.0
         """
+        if not self.probackup_old_path:
+            self.skipTest("You must specify PGPROBACKUPBIN_OLD"
+                          " for run this test")
         fname = self.id().split('.')[3]
         backup_dir = os.path.join(self.tmp_path, module_name, fname, 'backup')
         node = self.make_simple_node(
@@ -2951,6 +2956,9 @@ def test_partial_restore_backward_compatibility_merge(self):
         """
         old binary should be of version < 2.2.0
         """
+        if not self.probackup_old_path:
+            self.skipTest("You must specify PGPROBACKUPBIN_OLD"
+                          " for run this test")
         fname = self.id().split('.')[3]
         backup_dir = os.path.join(self.tmp_path, module_name, fname, 'backup')
         node = self.make_simple_node(
@@ -3643,7 +3651,9 @@ def test_pg_12_probackup_recovery_conf_compatibility(self):
 
         pg_probackup version must be 12 or greater
         """
-
+        if not self.probackup_old_path:
+            self.skipTest("You must specify PGPROBACKUPBIN_OLD"
+                          " for run this test")
         if self.pg_config_version < self.version_to_num('12.0'):
            return unittest.skip('You need PostgreSQL >= 12 for this test')
 
diff --git a/tests/show.py b/tests/show.py
index 2a13a768b..b1ebebf18 100644
--- a/tests/show.py
+++ b/tests/show.py
@@ -212,6 +212,9 @@ def test_corrupt_control_file(self):
     # @unittest.expectedFailure
     def test_corrupt_correctness(self):
         """backup.control contains invalid option"""
+        if not self.remote:
+            self.skipTest("You must enable PGPROBACKUP_SSH_REMOTE"
+                          " for run this test")
         fname = self.id().split('.')[3]
         backup_dir = os.path.join(self.tmp_path, module_name, fname, 'backup')
         node = self.make_simple_node(
@@ -232,12 +235,7 @@ def test_corrupt_correctness(self):
         output_local = self.show_pb(
             backup_dir, 'node', as_json=False, backup_id=backup_local_id)
 
-        if self.remote:
-            backup_remote_id = self.backup_node(backup_dir, 'node', node)
-        else:
-            backup_remote_id = self.backup_node(
-                backup_dir, 'node', node,
-                options=['--remote-proto=ssh', '--remote-host=localhost'])
+        backup_remote_id = self.backup_node(backup_dir, 'node', node)
 
         output_remote = self.show_pb(
             backup_dir, 'node', as_json=False, backup_id=backup_remote_id)
@@ -260,13 +258,8 @@ def test_corrupt_correctness(self):
             backup_dir, 'node', as_json=False, backup_id=backup_local_id)
         self.delete_pb(backup_dir, 'node', backup_local_id)
 
-        if self.remote:
-            backup_remote_id = self.backup_node(
-                backup_dir, 'node', node, backup_type='delta')
-        else:
-            backup_remote_id = self.backup_node(
-                backup_dir, 'node', node, backup_type='delta',
-                options=['--remote-proto=ssh', '--remote-host=localhost'])
+        backup_remote_id = self.backup_node(
+            backup_dir, 'node', node, backup_type='delta')
 
         output_remote = self.show_pb(
             backup_dir, 'node', as_json=False, backup_id=backup_remote_id)
@@ -290,13 +283,8 @@ def test_corrupt_correctness(self):
             backup_dir, 'node', as_json=False, backup_id=backup_local_id)
         self.delete_pb(backup_dir, 'node', backup_local_id)
 
-        if self.remote:
-            backup_remote_id = self.backup_node(
-                backup_dir, 'node', node, backup_type='page')
-        else:
-            backup_remote_id = self.backup_node(
-                backup_dir, 'node', node, backup_type='page',
-                options=['--remote-proto=ssh', '--remote-host=localhost'])
+        backup_remote_id = self.backup_node(
+            backup_dir, 'node', node, backup_type='page')
 
         output_remote = self.show_pb(
             backup_dir, 'node', as_json=False, backup_id=backup_remote_id)
@@ -318,6 +306,9 @@ def test_corrupt_correctness(self):
     # @unittest.expectedFailure
     def test_corrupt_correctness_1(self):
         """backup.control contains invalid option"""
+        if not self.remote:
+            self.skipTest("You must enable PGPROBACKUP_SSH_REMOTE"
+                          " for run this test")
         fname = self.id().split('.')[3]
         backup_dir = os.path.join(self.tmp_path, module_name, fname, 'backup')
         node = self.make_simple_node(
@@ -338,12 +329,7 @@ def test_corrupt_correctness_1(self):
         output_local = self.show_pb(
             backup_dir, 'node', as_json=False, backup_id=backup_local_id)
 
-        if self.remote:
-            backup_remote_id = self.backup_node(backup_dir, 'node', node)
-        else:
-            backup_remote_id = self.backup_node(
-                backup_dir, 'node', node,
-                options=['--remote-proto=ssh', '--remote-host=localhost'])
+        backup_remote_id = self.backup_node(backup_dir, 'node', node)
 
         output_remote = self.show_pb(
             backup_dir, 'node', as_json=False, backup_id=backup_remote_id)
@@ -370,13 +356,8 @@ def test_corrupt_correctness_1(self):
             backup_dir, 'node', as_json=False, backup_id=backup_local_id)
         self.delete_pb(backup_dir, 'node', backup_local_id)
 
-        if self.remote:
-            backup_remote_id = self.backup_node(
-                backup_dir, 'node', node, backup_type='delta')
-        else:
-            backup_remote_id = self.backup_node(
-                backup_dir, 'node', node, backup_type='delta',
-                options=['--remote-proto=ssh', '--remote-host=localhost'])
+        backup_remote_id = self.backup_node(
+            backup_dir, 'node', node, backup_type='delta')
 
         output_remote = self.show_pb(
             backup_dir, 'node', as_json=False, backup_id=backup_remote_id)
@@ -400,13 +381,8 @@ def test_corrupt_correctness_1(self):
             backup_dir, 'node', as_json=False, backup_id=backup_local_id)
         self.delete_pb(backup_dir, 'node', backup_local_id)
 
-        if self.remote:
-            backup_remote_id = self.backup_node(
-                backup_dir, 'node', node, backup_type='page')
-        else:
-            backup_remote_id = self.backup_node(
-                backup_dir, 'node', node, backup_type='page',
-                options=['--remote-proto=ssh', '--remote-host=localhost'])
+        backup_remote_id = self.backup_node(
+            backup_dir, 'node', node, backup_type='page')
 
         output_remote = self.show_pb(
             backup_dir, 'node', as_json=False, backup_id=backup_remote_id)
@@ -428,6 +404,9 @@ def test_corrupt_correctness_1(self):
     # @unittest.expectedFailure
     def test_corrupt_correctness_2(self):
         """backup.control contains invalid option"""
+        if not self.remote:
+            self.skipTest("You must enable PGPROBACKUP_SSH_REMOTE"
+                          " for run this test")
         fname = self.id().split('.')[3]
         backup_dir = os.path.join(self.tmp_path, module_name, fname, 'backup')
         node = self.make_simple_node(
diff --git a/tests/snapfs.py b/tests/snapfs.py
index a7f926c4c..991741952 100644
--- a/tests/snapfs.py
+++ b/tests/snapfs.py
@@ -10,9 +10,10 @@
 class SnapFSTest(ProbackupTest, unittest.TestCase):
 
     # @unittest.expectedFailure
-    @unittest.skipUnless(ProbackupTest.enterprise, 'skip')
     def test_snapfs_simple(self):
         """standart backup modes with ARCHIVE WAL method"""
+        if not self.enterprise:
+            self.skipTest('This test must be run on enterprise')
         fname = self.id().split('.')[3]
         node = self.make_simple_node(
             base_dir=os.path.join(module_name, fname, 'node'),
diff --git a/tests/validate.py b/tests/validate.py
index c5cc80733..0b04d92fe 100644
--- a/tests/validate.py
+++ b/tests/validate.py
@@ -1088,6 +1088,11 @@ def test_validate_instance_with_several_corrupt_backups_interrupt(self):
         """
         check that interrupt during validation is handled correctly
         """
+        if not self.gdb:
+            self.skipTest(
+                "Specify PGPROBACKUP_GDB and build without "
+                "optimizations for run this test"
+            )
         fname = self.id().split('.')[3]
         node = self.make_simple_node(
             base_dir=os.path.join(module_name, fname, 'node'),
diff --git a/travis/run_tests.sh b/travis/run_tests.sh
index 635b9f422..325b89060 100755
--- a/travis/run_tests.sh
+++ b/travis/run_tests.sh
@@ -35,7 +35,7 @@ git clone https://github.com/postgres/postgres.git -b $PG_BRANCH --depth=1
 # Compile and install Postgres
 echo "############### Compiling Postgres:"
 cd postgres # Go to postgres dir
-./configure --prefix=$PGHOME --enable-debug --enable-cassert --enable-depend --enable-tap-tests
+CFLAGS="-O0" ./configure --prefix=$PGHOME --enable-debug --enable-cassert --enable-depend --enable-tap-tests
 make -s -j$(nproc) install
 #make -s -j$(nproc) -C 'src/common' install
 #make -s -j$(nproc) -C 'src/port' install