Nicer error message on I/O error with child over pty #8686

Job	Run time
Test ./dev.sh	1m 19s
Test ./dev.sh	1m 19s
Linux (python=3.9 cc=gcc sanitize=0)	2m 6s
Linux (python=3.9 cc=gcc sanitize=0)	2m 6s
macOS Brew	3m 43s
macOS Brew	3m 20s
Linux (python=3.10 cc=gcc sanitize=1)	1m 52s
Linux (python=3.10 cc=gcc sanitize=1)	1m 52s
Bundle test (ubuntu-latest)	2m 3s
Bundle test (ubuntu-latest)	2m 3s
Bundle test (macos-latest)	3m 7s
Bundle test (macos-latest)	3m 7s
Linux package	11m 18s
Linux package	11m 18s
Linux (python=3.11 cc=clang sanitize=1)	2m 4s
Linux (python=3.11 cc=clang sanitize=1)	2m 4s
	54m 41s

Provide feedback