As below. $ bash -c 'declare -p BASH_VERSION' declare -- BASH_VERSION="5.2.15(1)-release" $ bash -c '[[ ]]; echo fin'; echo $? 0
$ bash -c 'declare -p BASH_VERSION' declare -- BASH_VERSION="5.1.16(1)-release" $ bash -c '[[ ]]; echo fin'; echo $? bash: -c: line 1: syntax error near `;' bash: -c: line 1: `[[ ]]; echo fin' 2 The development branch behaves as 5.1 does. Being uncertain as to whether this is a result of the issue having been identified prior, I determined that it was worth reporting. -- Kerin Millar
