mulle-nat / cmake-crazy

A demo of some cmake craziness

Stuff that drives you nuts

Create two "compilers" bar-cc:

#! /bin/sh

exec "cc" "$@"

and foo-cc:

#! /bin/sh

exec "${CC:-cc}" "$@"

and make them executable with chmod 755 bar-cc foo-cc.

Why and how is it possible that there is any noticable difference in foo-cc and bar-cc for cmake ?

Use this CMakeLists.txt:

project( crazy C)

Then run like this:

#! /bin/sh

PATH="${PWD}:$PATH"
unset CC

echo "bar-cc" >&2
echo >&2

[ -d build ] && rm -rf build

(
   mkdir build &&
   cd build &&
   cmake -DCMAKE_C_COMPILER=bar-cc ..
) || exit 1

[ -d build ] && rm -rf build

echo >&2
echo >&2
echo "foo-cc" >&2
echo >&2

(
   mkdir build &&
   cd build &&
   cmake -DCMAKE_C_COMPILER=foo-cc ..
) || exit 1

Now invoke cmake with

cmake -DCMAKE_C_COMPILER=${PWD}/foo-cc .`

and it will hang (with cmake version 3.18.4).

It will not hang with bar-cc.