[OE-core] [PATCH 1/1] oe-init-build-env: Error out when failed to locate cwd

[Robert Yang]

Ubuntu's /bin/sh symlinks to /bin/dash by default, so
subprocess.check_call(oe-init-build-env, cwd=builddir) would be failed since
pwd is builddir, and there is no $builddir/oe-init-build-env, this would
lead to other confusing errors, check and error it out earlier to make it
easier to locate the problem.

We don't meet the problem when manually run ". oe-init-build-env" is because
Ubuntu's default login shell is bash, but subprocess.check_call() doesn't
respect to login shell, so the error only happens in situations like
subprocess.check_call().

And also print errors to stderr as oe-buildenv-internal does.

Signed-off-by: Robert Yang <liezhi.yang at windriver.com>
---
 oe-init-build-env | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/oe-init-build-env b/oe-init-build-env
index e813230..861c3e0 100755
--- a/oe-init-build-env
+++ b/oe-init-build-env
@@ -31,13 +31,18 @@ elif [ -n "$ZSH_NAME" ]; then
     THIS_SCRIPT=$0
 else
     THIS_SCRIPT="$(pwd)/oe-init-build-env"
+    if [ ! -e "$THIS_SCRIPT" ]; then
+        echo "Error: $THIS_SCRIPT doesn't exist!" >&2
+        echo "Please run this script in oe-init-build-env's directory." >&2
+        exit 1
+    fi
 fi
 if [ -n "$BBSERVER" ]; then
     unset BBSERVER
 fi
 
 if [ -z "$ZSH_NAME" ] && [ "$0" = "$THIS_SCRIPT" ]; then
-    echo "Error: This script needs to be sourced. Please run as '. $THIS_SCRIPT'"
+    echo "Error: This script needs to be sourced. Please run as '. $THIS_SCRIPT'" >&2
     exit 1
 fi
 
-- 
2.7.4