io-qcow2-271 failure on alpine

Testing with make docker-test-full@alpine

we get

--- /tmp/qemu-test/src/tests/qemu-iotests/271.out
+++ /tmp/qemu-test/qcow2-file-271/271.out.bad
@@ -456,7 +456,7 @@
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1048576
 L2 entry #1: 0x8000000000060000 00000001ffffffff
 qcow2: Marking image as corrupt: Invalid cluster entry found  (L2 offset: 0x40000, L2 index: 0x1); further corruption events will be suppressed
-read failed: Input/output error
+read failed: I/O error

The pattern match needs to be improved for the strerror difference between glibc and musl.