Add a hint to PandA if we can't find a block (#668)

* Add a hint to PandA if we can't find a block

* Address review comments

.github/PULL_REQUEST_TEMPLATE/pull_request_template.md

@@ -6,3 +6,5 @@ Fixes #ISSUE
 
 ### Checks for reviewer
 - [ ] Would the PR title make sense to a user on a set of release notes
+- [ ] If the change requires a bump in an IOC version, is that specified in a `##Changes` section in the body of the PR
+- [ ] If the change requires a bump in the PandABlocks-ioc version, is the `ophyd_async.fastcs.panda._hdf_panda.MINIMUM_PANDA_IOC` variable updated to match

src/ophyd_async/epics/core/_pvi_connector.py

@@ -32,10 +32,11 @@ def _get_signal_details(entry: Entry) -> tuple[type[Signal], str, str]:
 
 
 class PviDeviceConnector(DeviceConnector):
-    def __init__(self, prefix: str = "") -> None:
+    def __init__(self, prefix: str = "", error_hint: str = "") -> None:
         # TODO: what happens if we get a leading "pva://" here?
         self.prefix = prefix
         self.pvi_pv = prefix + "PVI"
+        self.error_hint = error_hint
 
     def create_children_from_annotations(self, device: Device):
         if not hasattr(self, "filler"):
@@ -85,7 +86,8 @@ async def connect_real(
                     if e:
                         self._fill_child(name, e, i)
         # Check that all the requested children have been filled
-        self.filler.check_filled(f"{self.pvi_pv}: {entries}")
+        suffix = f"\n{self.error_hint}" if self.error_hint else ""
+        self.filler.check_filled(f"{self.pvi_pv}: {entries}{suffix}")
         # Set the name of the device to name all children
         device.set_name(device.name)
         return await super().connect_real(device, timeout, force_reconnect)

src/ophyd_async/fastcs/core.py

@@ -2,8 +2,8 @@
 from ophyd_async.epics.core import PviDeviceConnector
 
 
-def fastcs_connector(device: Device, uri: str) -> DeviceConnector:
+def fastcs_connector(device: Device, uri: str, error_hint: str = "") -> DeviceConnector:
     # TODO: add Tango support based on uri scheme
-    connector = PviDeviceConnector(uri)
+    connector = PviDeviceConnector(uri, error_hint)
     connector.create_children_from_annotations(device)
     return connector

src/ophyd_async/fastcs/panda/_hdf_panda.py

@@ -9,6 +9,8 @@
 from ._control import PandaPcapController
 from ._writer import PandaHDFWriter
 
+MINIMUM_PANDA_IOC = "0.11.4"
+
 
 class HDFPanda(CommonPandaBlocks, StandardDetector):
     def __init__(
@@ -18,8 +20,9 @@ def __init__(
         config_sigs: Sequence[SignalR] = (),
         name: str = "",
     ):
+        error_hint = f"Is PandABlocks-ioc at least version {MINIMUM_PANDA_IOC}?"
         # This has to be first so we make self.pcap
-        connector = fastcs_connector(self, prefix)
+        connector = fastcs_connector(self, prefix, error_hint)
         controller = PandaPcapController(pcap=self.pcap)
         writer = PandaHDFWriter(
             path_provider=path_provider,

tests/fastcs/panda/test_panda_connect.py

@@ -56,7 +56,9 @@ class CommonPandaBlocksNoData(Device):
 
     class Panda(CommonPandaBlocksNoData):
         def __init__(self, uri: str, name: str = ""):
-            super().__init__(name=name, connector=fastcs_connector(self, uri))
+            super().__init__(
+                name=name, connector=fastcs_connector(self, uri, "Is it ok?")
+            )
 
     yield Panda
 
@@ -124,7 +126,7 @@ async def test_panda_with_missing_blocks(panda_pva, panda_t):
         match=re.escape(
             "mypanda: cannot provision ['pcap'] from PANDAQSRVI:PVI: "
             "{'pulse': [None, {'d': 'PANDAQSRVI:PULSE1:PVI'}],"
-            " 'seq': [None, {'d': 'PANDAQSRVI:SEQ1:PVI'}]}"
+            " 'seq': [None, {'d': 'PANDAQSRVI:SEQ1:PVI'}]}\nIs it ok?"
         ),
     ):
         await panda.connect()