Bash is abnormal in Makefile!

Question

all,

I have found that the same Makefile works well in Mac OS X, but does not work in Ubuntu. The snippet is as following:

start:
    @echo $(seperator)
    @if [[ "$(PROJECT)" == "" ]]; then \
         echo " Project powered by CodeMate!"; \
     else \
         echo "  $(PROJECT)"; \
     fi
    @echo $(seperator)

and make complains:

/bin/sh: [[: not found

Any idea?

Cheers,

Li

---

Updates:

I have changed the above conditional Bash statements to:

if test "$(PROJECT)" = ""; then \

then things work fine. So what is wrong with "[["?

Answer 1

Place this at the top of your Makefile:

SHELL := /bin/bash # Use bash syntax

This happens because [[ is a builtin command of bash and you're running it with sh. The above line will set bash as default interpreter for the commands ran on makefile.

Answer 2

Makefiles use sh by default, not bash.

In Ubuntu sh point to dash, a POSIX compliant and minimalistic shell, not providing the [[ keywork.