Why getting "Build step 'Execute shell' marked build as failure" error while creating a backup tar for files



PHP Snippet 1:

echo "START" 
echo "-----GIT LOG-------" 
git log --pretty=format:"%H - %an, %ar, %ad : %s " -5  

git log --stat -1 
echo "------ARCHIVE------" 
tar -zcvf bblc.tar.gz *
exit 0

PHP Snippet 2:

-bash-4.2$ mkdir tmp
$ cd tmp
$ touch foo
$ tar -zcvf bblc.tar.gz *
foo
$ echo $?
0
$ tar -zcvf bblc.tar.gz *
bblc.tar.gz
tar: bblc.tar.gz: File shrank by 115 bytes; padding with zeros
foo
$ echo $?
1

PHP Snippet 3:

tar -zcvf /tmp/bblc.tar.gz * && mv /tmp/bblc.tar.gz ./

PHP Snippet 4:

tar -zcvf /tmp/bblc.tar.gz dir1 dir2 dir3 file1 file2

PHP Snippet 5:

tar -zcvf bblc.tar.gz * || true