Pyinstaller issues

I build my exe with
`pyinstaller a.py`

but a.exe has some issue when I run the files.
here is log.
```
Traceback (most recent call last):
File "a.py", line 38, in
File "", line 991, in _find_and_load
File "", line 975, in _find_and_load_unlocked
File "", line 671, in _load_unlocked
File "PyInstaller\loader\pyimod02_importers.py", line 499, in exec_module
File "vqml_srv.py", line 13, in
File "", line 991, in _find_and_load
File "", line 975, in _find_and_load_unlocked
File "", line 671, in _load_unlocked
File "PyInstaller\loader\pyimod02_importers.py", line 499, in exec_module
File "vqml.py", line 45, in
File "", line 991, in _find_and_load
File "", line 975, in _find_and_load_unlocked
File "", line 671, in _load_unlocked
File "PyInstaller\loader\pyimod02_importers.py", line 499, in exec_module
File "decord\__init__.py", line 4, in
File "", line 991, in _find_and_load
File "", line 975, in _find_and_load_unlocked
File "", line 671, in _load_unlocked
File "PyInstaller\loader\pyimod02_importers.py", line 499, in exec_module
File "decord\_ffi\runtime_ctypes.py", line 8, in
File "", line 991, in _find_and_load
File "", line 975, in _find_and_load_unlocked
File "", line 671, in _load_unlocked
File "PyInstaller\loader\pyimod02_importers.py", line 499, in exec_module
File "decord\_ffi\base.py", line 47, in
File "decord\_ffi\base.py", line 37, in _load_lib
File "decord\_ffi\libinfo.py", line 80, in find_lib_path
RuntimeError: Cannot find the files.
List of candidates:
D:\a\a\dist\b\decord\libdecord.dll
D:\a\a\dist\build\libdecord.dll
D:\a\a\dist\build\Release\libdecord.dll
D:\a\a\dist\lib\libdecord.dll
D:\a\a\libdecord.dll
D:\a\a\dist\vqml\decord\decord.dll
D:\a\a\dist\build\decord.dll
D:\a\a\dist\build\Release\decord.dll
D:\a\a\dist\lib\decord.dll
D:\a\a\decord.dll
[12392] Failed to execute script 'a' due to unhandled exception!
```

I found some error are quite frequently happen in pyinstaller.
It is the reason that the lib is built on C++?
How Can I get exe with pyinstaller that using decord?

Thx.