我正在尝试在linux(Ubuntu 18.04(上构建mailcore2库，但遇到了困难。(大多数情况下(按照他们的回购上的指示进行操作：https://github.com/MailCore/mailcore2/blob/master/build-linux/README.md
所以首先我安装依赖项(一切正常(：
sudo apt-get install libctemplate-dev libicu-dev libsasl2-dev libtidy-dev
uuid-dev libxml2-dev libglib2.0-dev autoconf automake libtool cmake
然后它指导如何构建 libetpan，但我使用的是 libtepan 存储库中的更新说明： https://github.com/dinhviethoa/libetpan：
git clone https://github.com/dinhviethoa/libetpan
cd libetpan
./autogen.sh
make
sudo make install
最后，我尝试构建MailCore：
git clone https://github.com/MailCore/mailcore2
cd mailcore2
mkdir build
cd build
cmake ..
make
但是无论我使用什么提交，我总是收到以下错误：
In file included from /home/<USER>/mailcore2/src/core/basetypes/MCString.h:7:0,
from /home/<USER>/mailcore2/src/core/basetypes/MCData.cpp:24:
/home/<USER>/mailcore2/build/src/include/MailCore/MCICUTypes.h:16:25: error: conflicting declaration ‘typedef short unsigned int UChar’
typedef __CHAR16_TYPE__ UChar;
^~~~~
In file included from /usr/include/unicode/utypes.h:38:0,
from /usr/include/unicode/ucsdet.h:24,
from /home/<USER>/mailcore2/src/core/basetypes/MCData.cpp:15:
/usr/include/unicode/umachine.h:347:22: note: previous declaration as ‘typedef char16_t UChar’
typedef char16_t UChar;
^~~~~
src/CMakeFiles/MailCore.dir/build.make:182: recipe for target 'src/CMakeFiles/MailCore.dir/core/basetypes/MCData.cpp.o' failed
make[2]: *** [src/CMakeFiles/MailCore.dir/core/basetypes/MCData.cpp.o] Error 1
CMakeFiles/Makefile2:85: recipe for target 'src/CMakeFiles/MailCore.dir/all' failed
make[1]: *** [src/CMakeFiles/MailCore.dir/all] Error 2
Makefile:83: recipe for target 'all' failed
make: *** [all] Error 2
我已经在iOS上使用它(通过CocoaPods(一段时间了，但想将我的电子邮件功能转移到服务器端。我在 Github 上打开了一个问题，但还没有牵引力。
In/home/<USER>/mailcore2/build/src/include/MailCore/MCICUTypes.h
取代：
typedef __CHAR16_TYPE__ UChar;
跟：
typedef char16_t UChar;
然后运行：
make clean
make