Brew zsh hangs on $(...) command substitution in Big Sur 11.0.1

[joelburton (Joel Burton)]

tart zsh without rcs (this should start a new shell):

/usr/local/bin/zsh --no-rcs

try to enter the following in the new shell (it should hang):

echo $(date)

To me it seems like all command substitution using $() causes zsh to hang. Backticks seem to work though.

(Copying report from ​https://github.com/Homebrew/discussions/discussions/141 ; this is about a problem with Homebrew, but I'm getting the same behavior with MacPorts0.