Note: This warning has been retired in favor of individual SC3xxx warnings for each individual issue. Removed in V0.7.2 - 2021-04-19

You are writing a script for dash, but you're using a feature that dash doesn't support. See SC2039, the equivalent warning for POSIX sh, for possible workarounds.

See also Ubuntu's DashAsBinSh migration guide for how to make bash-specific scripts dash-compatible.