Add CI and documentation for exceptions

Signed-off-by: Egor Savkin <es@m-labs.hk>

artiq/coredevice/comm_kernel.py

@@ -688,9 +688,9 @@ def read_exception_string():
 
         try:
             message = nested_exceptions[0][1].format(*nested_exceptions[0][2])
-        except Exception as ex:
+        except:
             message = nested_exceptions[0][1]
-            logger.error("Couldn't format exception message `{}`: {}: {}".format(message, type(ex).__name__, str(ex)))
+            logger.error("Couldn't format exception message", exc_info=True)
 
         try:
             python_exn = python_exn_type(message)

artiq/coredevice/exceptions.py

@@ -15,7 +15,12 @@
 
 
 class CoreException:
-    """Information about an exception raised or passed through the core device."""
+    """Information about an exception raised or passed through the core device.
+
+     If the exception message contains positional format arguments, it
+     will attempt to substitute them with the provided parameters.
+     If the substitution fails, the original message will remain unchanged.
+    """
     def __init__(self, exceptions, exception_info, traceback, stack_pointers):
         self.exceptions = exceptions
         self.exception_info = exception_info

artiq/test/coredevice/test_exceptions.py

@@ -1,4 +1,3 @@
-import logging
 import re
 
 from artiq.experiment import *
@@ -54,7 +53,6 @@ def build(self):
         except DeviceError:
             self.led = self.get_device("led0")
 
-
     @kernel
     def run(self):
         self.core.reset()
@@ -68,8 +66,9 @@ def test_custom_formatted_kernel_exception(self):
         with self.assertLogs() as captured:
             with self.assertRaisesRegex(CustomException, r"CustomException\(\d+\): \{foo\}"):
                 self.execute(KernelFmtException)
-        self.assertEqual(captured.output, [
-            "ERROR:artiq.coredevice.comm_kernel:Couldn't format exception message `{foo}`: KeyError: 'foo'"])
+        captured_lines = captured.output[0].split('\n')
+        self.assertEqual([captured_lines[0], captured_lines[-1]],
+                         ["ERROR:artiq.coredevice.comm_kernel:Couldn't format exception message", "KeyError: 'foo'"])
 
     def test_nested_formatted_kernel_exception(self):
         with self.assertLogs() as captured:
@@ -78,8 +77,9 @@ def test_nested_formatted_kernel_exception(self):
                                             r"CustomException\(\d+\): \{foo\}.*?RTIOUnderflow\(\d+\): \{bar\}.*?RTIOOverflow\(\d+\): \{bizz\}.*?RTIOUnderflow\(\d+\): \{buzz\}",
                                             re.DOTALL)):
                 self.execute(KernelNestedFmtException)
-        self.assertEqual(captured.output, [
-            "ERROR:artiq.coredevice.comm_kernel:Couldn't format exception message `{foo}`: KeyError: 'foo'"])
+        captured_lines = captured.output[0].split('\n')
+        self.assertEqual([captured_lines[0], captured_lines[-1]],
+                         ["ERROR:artiq.coredevice.comm_kernel:Couldn't format exception message", "KeyError: 'foo'"])
 
     def test_rtio_underflow(self):
         with self.assertLogs() as captured:
@@ -88,4 +88,5 @@ def test_rtio_underflow(self):
                                             r"RTIO underflow at channel 0x\d+?:led\d*?, \d+? mu, slack -\d+? mu.*?RTIOUnderflow\(\d+\): RTIO underflow at channel 0x\d+?:led\d+?, \d+? mu, slack -\d+? mu",
                                             re.DOTALL)):
                 self.execute(KernelRTIOUnderflow)
-        self.assertEqual(captured.output, ["WARNING:artiq.coredevice.comm_kernel:sequence error(s) reported during kernel execution"])
+        self.assertEqual(captured.output[0].split('\n')[0],
+                         "WARNING:artiq.coredevice.comm_kernel:sequence error(s) reported during kernel execution")

flake.nix

@@ -521,11 +521,15 @@
               # Read "Ok" line when remote successfully locked
               read LOCK_OK
 
+              export ARTIQ_ROOT=`python -c "import artiq; print(artiq.__path__[0])"`/examples/kc705_nist_clock
+              export ARTIQ_LOW_LATENCY=1
+
+              artiq_rtiomap --device-db $ARTIQ_ROOT/device_db.py device_map.bin
+              artiq_mkfs -s ip `python -c "import artiq.examples.kc705_nist_clock.device_db as ddb; print(ddb.core_addr)"`/24 -f device_map device_map.bin kc705_nist_clock.config
+              artiq_flash -t kc705 -H rpi-1 storage -f kc705_nist_clock.config
               artiq_flash -t kc705 -H rpi-1 -d ${packages.x86_64-linux.artiq-board-kc705-nist_clock}
               sleep 30
 
-              export ARTIQ_ROOT=`python -c "import artiq; print(artiq.__path__[0])"`/examples/kc705_nist_clock
-              export ARTIQ_LOW_LATENCY=1
               python -m unittest discover -v artiq.test.coredevice
             )