build error

[caidaol]

�when I try to build, i fond this error. who can help me? help.

C:/msys64/home/Administrator/libQtShadowsocks-2.0.0/lib/cipher.cpp:212:42: required from here
C:/msys64/mingw64/include/c++/9.2.0/bits/unique_ptr.h:79:16: error: invalid application of 'sizeof' to incomplete type 'Botan::Keyed_Filter'
79 | static_assert(sizeof(_Tp)>0,
| ^~~~~~~~~~~
[ 31%] Building CXX object lib/CMakeFiles/QtShadowsocks.dir/rc4.cpp.obj
make[2]: *** [lib/CMakeFiles/QtShadowsocks.dir/build.make:115：lib/CMakeFiles/QtShadowsocks.dir/cipher.cpp.obj] 错误 1
make[2]: *** 正在等待未完成的任务....
make[1]: *** [CMakeFiles/Makefile2:101：lib/CMakeFiles/QtShadowsocks.dir/all] 错误 2
make: *** [Makefile:130：all] 错误 2

[caidaol]

other step is right, like this:

Administrator@WIN-A5NCTOR9FS3 MINGW64 ~/libQtShadowsocks-2.0.0/build

cmake -G "MSYS Makefiles" .. -DUSE_BOTAN2=ON -DCMAKE_INSTALL_PREFIX=/mingw64

-- The CXX compiler identification is GNU 9.2.0
-- Check for working CXX compiler: C:/msys64/mingw64/bin/g++.exe
-- Check for working CXX compiler: C:/msys64/mingw64/bin/g++.exe -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Found PkgConfig: C:/msys64/mingw64/bin/pkg-config.exe (found version "0.29.2")
-- Checking for module 'botan-2>=2.3.0'
-- Found botan-2, version 2.12.0
-- Configuring done
-- Generating done
-- Build files have been written to: C:/msys64/home/Administrator/libQtShadowsocks-2.0.0/build

[caidaol]

Update cipher.cpp

#218