make: "varmod-assign-shell.mk" line 21: warning: Command "echo output; (exit 13)" exited with status 13
Global: _ = # (empty)
Var_Parse: ${ASSIGNED::!=echo output; ${:U(exit 13)}} (eval-keep-dollar-and-undefined)
Evaluating modifier ${ASSIGNED::...} on value "previous" (eval-keep-dollar-and-undefined, regular)
Modifier part: "echo output; (exit 13)"
Capturing the output of command "echo output; (exit 13)"
make: "varmod-assign-shell.mk" line 26: warning: Command "echo output; (exit 13)" exited with status 13
Result of ${ASSIGNED::!=echo output; ${:U(exit 13)}} is "" (eval-keep-dollar-and-undefined, regular)
Global: _ = # (empty)
Global: .MAKEFLAGS =  -r -k -d v -d
Global: .MAKEFLAGS =  -r -k -d v -d 0
DIRECT=output
ASSIGNED=previous
exit status 0