Abort other fetches when resolution fails

micropip/_compat_in_pyodide.py

@@ -1,3 +1,4 @@
+from asyncio import CancelledError
 from pathlib import Path
 from urllib.parse import urlparse
 
@@ -7,7 +8,7 @@
 
 try:
     import pyodide_js
-    from js import Object
+    from js import AbortController, Object
     from pyodide_js import loadedPackages, loadPackage
     from pyodide_js._api import (  # type: ignore[import]
         loadBinaryFile,
@@ -21,6 +22,24 @@
         raise
     # Otherwise, this is pytest test collection so let it go.
 
+if IN_BROWSER:
+
+    async def _pyfetch(url: str, **kwargs):
+        if "signal" in kwargs:
+            return await pyfetch(url, **kwargs)
+
+        controller = AbortController.new()
+        kwargs["signal"] = controller.signal
+
+        try:
+            return await pyfetch(url, **kwargs)
+        except CancelledError:
+            controller.abort()
+            raise
+
+else:
+    _pyfetch = pyfetch
+
 
 async def fetch_bytes(url: str, kwargs: dict[str, str]) -> bytes:
     parsed_url = urlparse(url)
@@ -29,13 +48,13 @@ async def fetch_bytes(url: str, kwargs: dict[str, str]) -> bytes:
     if parsed_url.scheme == "file":
         return (await loadBinaryFile(parsed_url.path)).to_bytes()
 
-    return await (await pyfetch(url, **kwargs)).bytes()
+    return await (await _pyfetch(url, **kwargs)).bytes()
 
 
 async def fetch_string_and_headers(
     url: str, kwargs: dict[str, str]
 ) -> tuple[str, dict[str, str]]:
-    response = await pyfetch(url, **kwargs)
+    response = await _pyfetch(url, **kwargs)
 
     content = await response.string()
     # TODO: replace with response.headers when pyodide>= 0.24 is released

micropip/transaction.py

@@ -52,7 +52,17 @@ async def gather_requirements(
         for requirement in requirements:
             requirement_promises.append(self.add_requirement(requirement))
 
-        await asyncio.gather(*requirement_promises)
+        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
 
     async def add_requirement(self, req: str | Requirement) -> None:
         if isinstance(req, Requirement):