Add error field to AnalysisEnd event

Summary:
Adds an `error` field to the `AnalysisEnd` buck2_data event so downstream consumers can tell whether a target's analysis succeeded or failed. This mirrors the existing `error` field on `LoadBuildFileEnd`: it is `Some(message)` on failure and `None` on success.

landed-with-radar-review

Reviewed By: IanChilds

Differential Revision: D109932996

fbshipit-source-id: b2a7dc9a041ba119219f4f943d495eaae741339a

Author: scottcao

app/buck2_action_impl/src/dynamic/deferred.rs

@@ -338,6 +338,8 @@ async fn execute_lambda(
                     Ok((token, finalized))
                 });
 
+                let error = output.as_ref().err().map(|e| format!("{e:#}"));
+
                 (
                     output,
                     buck2_data::AnalysisEnd {
@@ -348,6 +350,7 @@ async fn execute_lambda(
                         profile: None,
                         declared_actions,
                         declared_artifacts,
+                        error,
                     },
                 )
             })

app/buck2_analysis/src/analysis/calculation.rs

@@ -336,6 +336,8 @@ async fn get_analysis_result_inner(
                             MaybeCompatible::Compatible(result)
                         };
 
+                        let error = result.as_ref().err().map(|e| format!("{e:#}"));
+
                         (
                             (result, split_instants),
                             buck2_data::AnalysisEnd {
@@ -344,6 +346,7 @@ async fn get_analysis_result_inner(
                                 profile,
                                 declared_actions,
                                 declared_artifacts,
+                                error,
                             },
                         )
                     })

app/buck2_anon_target/src/anon_targets.rs

@@ -483,6 +483,7 @@ impl AnonTargetKey {
                     profile: None, // Not implemented for anon targets
                     declared_actions: res.as_ref().ok().map(|(v, _)| v.num_declared_actions),
                     declared_artifacts: res.as_ref().ok().map(|(v, _)| v.num_declared_artifacts),
+                    error: res.as_ref().err().map(|e| format!("{e:#}")),
                 };
                 (res, end)
             },

app/buck2_data/data.proto

@@ -2093,6 +2093,7 @@ message AnalysisEnd {
   AnalysisProfile profile = 2;
   optional uint64 declared_actions = 6;
   optional uint64 declared_artifacts = 7;
+  optional string error = 8;
 }
 
 message AnalysisStageStart {