Support shell detection in helper mode

kart.spec

@@ -115,6 +115,7 @@ pyi_analysis = Analysis(
         '_cffi_backend',
         # via a cython module ???
         'csv',
+        'shellingham.posix',
         *collect_submodules('kart'),
         *collect_submodules('sqlalchemy'),
     ],

kart/completion.py

@@ -15,6 +15,10 @@
 except ImportError:
     shellingham = None
 
+def provide_default_shell():
+    if os.name == 'posix':
+        return os.environ['SHELL']
+    raise NotImplementedError(f'OS {os.name!r} support not available')
 
 class Shells(str, Enum):
     bash = "bash"
@@ -187,7 +191,10 @@ def install(
     if complete_var is None:
         complete_var = "_{}_COMPLETE".format(prog_name.replace("-", "_").upper())
     if shell is None and shellingham is not None:
-        shell, _ = shellingham.detect_shell()
+        try:
+            shell, _ = shellingham.detect_shell()
+        except shellingham.ShellDetectionFailure:
+            shell = os.path.basename(provide_default_shell())
     if shell == "bash":
         installed_path = install_bash(
             prog_name=prog_name, complete_var=complete_var, shell=shell

kart/helper.py

@@ -5,6 +5,7 @@
 import io
 import os
 import sys
+import traceback
 
 import click
 
@@ -203,9 +204,11 @@ class struct_semun(ctypes.Union):
                         )
 
                     except Exception as e:
+                        print(os.environ)
                         print(
-                            f"kart helper: unhandled exception [{e}]"
+                            f"kart helper: unhandled exception"
                         )  # TODO - should ext-run capture/handle this?
+                        traceback.print_exc(file=sys.stdout)
                         libc.semctl(semid, 0, SETVAL, struct_semun(val=1001))
                     try:
                         # send a signal to caller that we are done

tests/scripts/e2e-1.sh

@@ -33,6 +33,8 @@ set -x
 
 echo "Using helper mode: ${KART_USE_HELPER:-0}"
 
+kart -vvvv config --install-tab-completion auto
+
 kart init --initial-branch=main .
 kart config user.name "Kart E2E Test 1"
 kart config user.email "kart-e2e-test-1@email.invalid"