--- a/testing/mozharness/mozharness/mozilla/testing/firefox_media_tests.py
+++ b/testing/mozharness/mozharness/mozilla/testing/firefox_media_tests.py
@@ -293,16 +293,17 @@ class FirefoxMediaTestsBase(TestingMixin
             config=self.config,
             log_obj=self.log_obj,
             error_list=self.error_list
         )
 
         env = self.query_env()
         if self.query_minidump_stackwalk():
             env['MINIDUMP_STACKWALK'] = self.minidump_stackwalk_path
+        env['RUST_BACKTRACE'] = '1'
 
         if self.config['allow_software_gl_layers']:
             env['MOZ_LAYERS_ALLOW_SOFTWARE_GL'] = '1'
 
         return_code = self.run_command(
             cmd,
             output_timeout=self.test_timeout,
             output_parser=self.job_result_parser,

--- a/testing/mozharness/mozharness/mozilla/testing/firefox_ui_tests.py
+++ b/testing/mozharness/mozharness/mozilla/testing/firefox_ui_tests.py
@@ -236,16 +236,17 @@ class FirefoxUITests(TestingMixin, VCSTo
         tests = [os.path.join(dirs['abs_fxui_dir'], 'tests', test) for test in self.default_tests]
         cmd.extend(tests)
 
         # Set further environment settings
         env = env or self.query_env()
         env.update({'MINIDUMP_SAVE_PATH': dirs['abs_blob_upload_dir']})
         if self.query_minidump_stackwalk():
             env.update({'MINIDUMP_STACKWALK': self.minidump_stackwalk_path})
+        env['RUST_BACKTRACE'] = '1'
 
         if self.config['allow_software_gl_layers']:
             env['MOZ_LAYERS_ALLOW_SOFTWARE_GL'] = '1'
 
         return_code = self.run_command(cmd,
                                        cwd=dirs['abs_work_dir'],
                                        output_timeout=300,
                                        output_parser=parser,

--- a/testing/mozharness/mozharness/mozilla/testing/talos.py
+++ b/testing/mozharness/mozharness/mozilla/testing/talos.py
@@ -432,16 +432,17 @@ class Talos(TestingMixin, MercurialScrip
         self.run_command([python, "--version"])
         parser = TalosOutputParser(config=self.config, log_obj=self.log_obj,
                                    error_list=TalosErrorList)
         env = {}
         env['MOZ_UPLOAD_DIR'] = self.query_abs_dirs()['abs_blob_upload_dir']
         if not self.run_local:
             env['MINIDUMP_STACKWALK'] = self.query_minidump_stackwalk()
         env['MINIDUMP_SAVE_PATH'] = self.query_abs_dirs()['abs_blob_upload_dir']
+        env['RUST_BACKTRACE'] = '1'
         if not os.path.isdir(env['MOZ_UPLOAD_DIR']):
             self.mkdir_p(env['MOZ_UPLOAD_DIR'])
         env = self.query_env(partial_env=env, log_level=INFO)
         # adjust PYTHONPATH to be able to use talos as a python package
         if 'PYTHONPATH' in env:
             env['PYTHONPATH'] = self.talos_path + os.pathsep + env['PYTHONPATH']
         else:
             env['PYTHONPATH'] = self.talos_path

--- a/testing/mozharness/scripts/android_emulator_unittest.py
+++ b/testing/mozharness/scripts/android_emulator_unittest.py
@@ -756,16 +756,17 @@ class AndroidEmulatorTest(BlobUploadMixi
             cwd = self._query_tests_dir()
         except:
             self.fatal("Don't know how to run --test-suite '%s'!" % self.test_suite)
         env = self.query_env()
         if self.query_minidump_stackwalk():
             env['MINIDUMP_STACKWALK'] = self.minidump_stackwalk_path
         env['MOZ_UPLOAD_DIR'] = self.query_abs_dirs()['abs_blob_upload_dir']
         env['MINIDUMP_SAVE_PATH'] = self.query_abs_dirs()['abs_blob_upload_dir']
+        env['RUST_BACKTRACE'] = '1'
 
         self.info("Running on %s the command %s" % (self.emulator["name"], subprocess.list2cmdline(cmd)))
         self.info("##### %s log begins" % self.test_suite)
 
         # TinderBoxPrintRe does not know about the '-debug' categories
         aliases = {
             'reftest-debug': 'reftest',
             'jsreftest-debug': 'jsreftest',

--- a/testing/mozharness/scripts/desktop_unittest.py
+++ b/testing/mozharness/scripts/desktop_unittest.py
@@ -692,16 +692,17 @@ class DesktopUnittest(TestingMixin, Merc
                     parser.formatter = ref_formatter.ReftestFormatter()
 
                 if self.query_minidump_stackwalk():
                     env['MINIDUMP_STACKWALK'] = self.minidump_stackwalk_path
                 if self.query_nodejs():
                     env['MOZ_NODE_PATH'] = self.nodejs_path
                 env['MOZ_UPLOAD_DIR'] = self.query_abs_dirs()['abs_blob_upload_dir']
                 env['MINIDUMP_SAVE_PATH'] = self.query_abs_dirs()['abs_blob_upload_dir']
+                env['RUST_BACKTRACE'] = '1'
                 if not os.path.isdir(env['MOZ_UPLOAD_DIR']):
                     self.mkdir_p(env['MOZ_UPLOAD_DIR'])
 
                 if self.config['allow_software_gl_layers']:
                     env['MOZ_LAYERS_ALLOW_SOFTWARE_GL'] = '1'
 
                 env = self.query_env(partial_env=env, log_level=INFO)
                 cmd_timeout = self.get_timeout_for_category(suite_category)

--- a/testing/mozharness/scripts/marionette.py
+++ b/testing/mozharness/scripts/marionette.py
@@ -302,16 +302,17 @@ class MarionetteTest(TestingMixin, Mercu
         cmd.extend(self.query_tests_args(try_tests,
                                          str_format_values=config_fmt_args))
 
         env = {}
         if self.query_minidump_stackwalk():
             env['MINIDUMP_STACKWALK'] = self.minidump_stackwalk_path
         env['MOZ_UPLOAD_DIR'] = self.query_abs_dirs()['abs_blob_upload_dir']
         env['MINIDUMP_SAVE_PATH'] = self.query_abs_dirs()['abs_blob_upload_dir']
+        env['RUST_BACKTRACE'] = '1'
 
         if self.config['allow_software_gl_layers']:
             env['MOZ_LAYERS_ALLOW_SOFTWARE_GL'] = '1'
 
         if not os.path.isdir(env['MOZ_UPLOAD_DIR']):
             self.mkdir_p(env['MOZ_UPLOAD_DIR'])
         env = self.query_env(partial_env=env)
 

--- a/testing/mozharness/scripts/web_platform_tests.py
+++ b/testing/mozharness/scripts/web_platform_tests.py
@@ -235,16 +235,17 @@ class WebPlatformTest(TestingMixin, Merc
         dirs = self.query_abs_dirs()
         cmd = self._query_cmd()
 
         parser = StructuredOutputParser(config=self.config,
                                         log_obj=self.log_obj,
                                         log_compact=True)
 
         env = {'MINIDUMP_SAVE_PATH': dirs['abs_blob_upload_dir']}
+        env['RUST_BACKTRACE'] = '1'
 
         if self.config['allow_software_gl_layers']:
             env['MOZ_LAYERS_ALLOW_SOFTWARE_GL'] = '1'
 
         env = self.query_env(partial_env=env, log_level=INFO)
 
         return_code = self.run_command(cmd,
                                        cwd=dirs['abs_work_dir'],