ninjaCheckPhase hangs in flakes/develop test

[edolstra]

Describe the bug

# ninjaCheckPhase
+(develop.sh:128) expectStderr 0 nix develop --ignore-env --set-env-var FOO BAR --ignore-env .#hello
+(/home/eelco/Dev/nix/tests/functional/common/functions.sh:197) local expected res
+(/home/eelco/Dev/nix/tests/functional/common/functions.sh:198) expected=0
+(/home/eelco/Dev/nix/tests/functional/common/functions.sh:199) shift
+(/home/eelco/Dev/nix/tests/functional/common/functions.sh:200) nix develop --ignore-env --set-env-var FOO BAR --ignore-env .#hello
...
184/184 nix-functional-tests:flakes / develop                               TIMEOUT        300.02s   killed by signal 15 SIGTERM

It's hanging in bash:

eelco     812433  761382  0 14:08 pts/5    00:00:00             /nix/store/5w07wfs288qpmnvjywk24f3ak5k1np7r-python3-3.11.9/bin/python3.11 /nix/store/sszlpg1ckgfdkqamw539c2rlsrjgmqvl-meson-1.4.2/bin/meson test develop
eelco     812911  812433  0 14:08 ?        00:00:00               /nix/store/wckka8fxv4h5hp74cbkhaw3fw7kbvcs1-bash-5.2p26/bin/bash -x -e -u -o pipefail develop.sh
eelco     813034  812911  0 14:08 ?        00:00:00                 bash --rcfile /tmp/nix-shell.oJW4sJ/nix-shell.7dF2vv

which seems to be stuck reading from stdin:

# strace -p 813034
strace: Process 813034 attached
read(0, 0x4f06a0, 1)                    = ? ERESTARTSYS (To be restarted if SA_RESTART is set)

Steps To Reproduce

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Expected behavior

A clear and concise description of what you expected to happen.

nix-env --version output

Additional context

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