verify if cwd is an absolute path and env is valid
verify if cwd is an absolute path and env is valid

Signed-off-by: liang chenye <49f3f795d1fda22b7f7dfee719201384e22b7d55@huawei.com>

opencontainers/ocitools,opencontainers/runtime-tools,hmeng-19/ocitools,hmeng-19/ocitools,opencontainers/ocitools,liangchenye/ocitools,wking/ocitools-v2,wking/ocitools-v2,liangchenye/ocitools,opencontainers/runtime-tools