ci: Resolve an issue calculating workflow variables

PRs are now getting the following:

    Traceback (most recent call last):
      File "/home/runner/work/compiler-builtins/compiler-builtins/ci/ci-util.py", line 510, in <module>
        main()
      File "/home/runner/work/compiler-builtins/compiler-builtins/ci/ci-util.py", line 496, in main
        ctx.emit_workflow_output()
      File "/home/runner/work/compiler-builtins/compiler-builtins/ci/ci-util.py", line 294, in emit_workflow_output
        pr = PrInfo.from_env()
             ^^^^^^^^^^^^^^^^^
      File "/home/runner/work/compiler-builtins/compiler-builtins/ci/ci-util.py", line 152, in from_env
        return cls.from_pr(pr_env)
               ^^^^^^^^^^^^^^^^^^^
      File "/home/runner/work/compiler-builtins/compiler-builtins/ci/ci-util.py", line 174, in from_pr
        return cls(**json.loads(pr_info), cfg=PrCfg(pr_json["body"]))
                                              ^^^^^^^^^^^^^^^^^^^^^^
      File "/home/runner/work/compiler-builtins/compiler-builtins/ci/ci-util.py", line 134, in __init__
        pprint.pp(self)
      File "/usr/lib/python3.12/pprint.py", line 66, in pp
        pprint(object, *args, sort_dicts=sort_dicts, **kwargs)
    ...
    AttributeError: 'PrCfg' object has no attribute 'extra_extensive'. Did you mean: 'skip_extensive'?

Resolve this by using `__post_init__` rather than `__init__`.

Author: tgross35

ci/ci-util.py

@@ -71,19 +71,21 @@ def eprint(*args, **kwargs):
     print(*args, file=sys.stderr, **kwargs)
 
 
-@dataclass(init=False)
+@dataclass(kw_only=True)
 class PrCfg:
     """Directives that we allow in the commit body to control test behavior.
 
     These are of the form `ci: foo`, at the start of a line.
     """
 
+    # The PR body
+    body: str
     # Skip regression checks (must be at the start of a line).
     allow_regressions: bool = False
     # Don't run extensive tests
     skip_extensive: bool = False
     # Add these extensive tests to the list
-    extra_extensive: list[str] = field(default_factory=list)
+    extra_extensive: list[str] = field(default_factory=list, init=False)
 
     # Allow running a large number of extensive tests. If not set, this script
     # will error out if a threshold is exceeded in order to avoid accidentally
@@ -103,10 +105,10 @@ class PrCfg:
     DIR_TEST_LIBM: str = "test-libm"
     DIR_EXTRA_EXTENSIVE: str = "extra-extensive"
 
-    def __init__(self, body: str):
+    def __post_init__(self):
         directives = re.finditer(
             r"^\s*ci:\s*(?P<dir_name>[^\s=]*)(?:\s*=\s*(?P<args>.*))?",
-            body,
+            self.body,
             re.MULTILINE,
         )
         for dir in directives:
@@ -171,7 +173,8 @@ def from_pr(cls, pr_number: int | str) -> Self:
         )
         pr_json = json.loads(pr_info)
         eprint("PR info:", json.dumps(pr_json, indent=4))
-        return cls(**json.loads(pr_info), cfg=PrCfg(pr_json["body"]))
+        print(f"JB: {pr_json["body"]}")
+        return cls(**pr_json, cfg=PrCfg(body=pr_json["body"]))
 
 
 class FunctionDef(TypedDict):