GNU Make's bug (exec a directory)

make-a-bug.sh

#!/bin/sh

set -x

# Create a folder named 'docker'. The folder would have 'executible' flag set
mkdir -p `pwd`/scripts/docker

# Add the script to the path BEFORE the rest
export PATH=`pwd`/scripts:$PATH

# Create a simple Makefile to run a docker command

cat<<EOF > Makefile
all:
	docker ps
EOF

# Run the make command
make

# The output would be
#   docker ps
#   make: docker: Permission denied


# `strace` would reveal the mystery (with some sed magic to strip the private stuff)
strace -f -e execve make 2>&1 | sed "s|/home/$(whoami)/.*/scripts/docker|/path/to/scripts/docker|g"

# The output would be like:
#
#   execve("/usr/bin/make", ["make"], 0x7ffd59f59e68 /* 72 vars */) = 0
#   docker ps
#   strace: Process 2833630 attached
#   [pid 2833630] execve("/path/to/scripts/docker", ["docker", "ps"], 0x55884ea326f0 /* 75 vars */) = -1 EACCES (Permission denied)
#   [pid 2833630] +++ exited with 127 +++
#   make: docker: Permission denied
#   make: *** [Makefile:2: all] Error 127

# Looks like make does not care if a command is a directory, but just checks for 'x' flag.