Only hack botocore when needed (#31610)

Newer versions of botocore (>=1.23.47) support the full IOBase
interface, so the hacks added to supplement the missing attributes are
no longer needed. Conditionally disable the hacks if they appear to be
unnecessary based on the class hierarchy found at runtime.

1 files changed, 10 insertions, 6 deletions

diff --git a/lib/spack/spack/s3_handler.py b/lib/spack/spack/s3_handler.py
index 9f775abafb..932ba4611d 100644
--- a/lib/spack/spack/s3_handler.py
+++ b/lib/spack/spack/s3_handler.py
@@ -3,7 +3,7 @@
 #
 # SPDX-License-Identifier: (Apache-2.0 OR MIT)
 
-from io import BufferedReader
+from io import BufferedReader, IOBase
 
 import six
 import six.moves.urllib.error as urllib_error
@@ -23,11 +23,15 @@ import spack.util.url as url_util
 # https://github.com/python/cpython/pull/3249
 class WrapStream(BufferedReader):
     def __init__(self, raw):
-        raw.readable = lambda: True
-        raw.writable = lambda: False
-        raw.seekable = lambda: False
-        raw.closed = False
-        raw.flush = lambda: None
+        # In botocore >=1.23.47, StreamingBody inherits from IOBase, so we
+        # only add missing attributes in older versions.
+        # https://github.com/boto/botocore/commit/a624815eabac50442ed7404f3c4f2664cd0aa784
+        if not isinstance(raw, IOBase):
+            raw.readable = lambda: True
+            raw.writable = lambda: False
+            raw.seekable = lambda: False
+            raw.closed = False
+            raw.flush = lambda: None
         super(WrapStream, self).__init__(raw)
 
     def detach(self):