use asyncio.TaskGroup to automatically cancel other jobs when one f…

…ails

micropip/transaction.py

@@ -37,6 +37,8 @@ class Transaction:
 
     verbose: bool | int = False
 
+    tg: asyncio.TaskGroup | None = None
+
     def __post_init__(self):
         # If index_urls is None, pyodide-lock.json have to be searched first.
         # TODO: when PyPI starts to support hosting WASM wheels, this might be deleted.
@@ -48,21 +50,15 @@ async def gather_requirements(
         self,
         requirements: list[str] | list[Requirement],
     ) -> None:
-        requirement_promises = []
-        for requirement in requirements:
-            requirement_promises.append(self.add_requirement(requirement))
-
-        futures: list[asyncio.Future] = []
-        try:
-            for coro in requirement_promises:
-                futures.append(asyncio.ensure_future(coro))
-            await asyncio.gather(*futures)
-        except ValueError:
-            if not self.keep_going:
-                for future in futures:
-                    if not future.done():
-                        future.cancel()
-            raise
+        if self.tg:
+            for requirement in requirements:
+                self.tg.create_task(self.add_requirement(requirement))
+        else:
+            async with asyncio.TaskGroup() as tg:
+                self.tg = tg  # only one task group from the top level
+                for requirement in requirements:
+                    tg.create_task(self.add_requirement(requirement))
+            self.tg = None
 
     async def add_requirement(self, req: str | Requirement) -> None:
         if isinstance(req, Requirement):