Hi!
I'm trying to build LO Online on Arch Linux ARM and every time whole things are ending from very end of make with error at Admin.o module. Here is compiler output:

make  all-recursive
make[1]: Entering directory '/mnt/usbstick/lool_co_git'
Making all in .
make[2]: Entering directory '/mnt/usbstick/lool_co_git'
  CXX      wsd/Admin.o
In file included from ./wsd/LOOLWebSocket.hpp:22:0,
                 from wsd/AdminModel.hpp:20,
                 from wsd/Admin.hpp:23,
                 from wsd/Admin.cpp:28:
./common/Protocol.hpp: In function 'std::__cxx11::string LOOLProtocol::getAbbreviatedMessage(const string&)':
./common/Protocol.hpp:268:93: error: no matching function for call to 'min(std::__cxx11::basic_string<char>::size_type, long unsigned int)'
  = getDelimiterPosition(message.data(), std::min(message.size(), 500UL), '\n');
                                                                       ^
In file included from /usr/include/c++/6.3.1/bits/char_traits.h:39:0,
                 from /usr/include/c++/6.3.1/string:40,
                 from /usr/include/c++/6.3.1/stdexcept:39,
                 from /usr/include/c++/6.3.1/array:39,
                 from /usr/include/c++/6.3.1/tuple:39,
                 from /usr/include/c++/6.3.1/mutex:38,
                 from wsd/Admin.cpp:13:
/usr/include/c++/6.3.1/bits/stl_algobase.h:195:5: note: candidate: template<class _Tp> const _Tp& std::min(const _Tp&, const _Tp&)
     min(const _Tp& __a, const _Tp& __b)
     ^~~
/usr/include/c++/6.3.1/bits/stl_algobase.h:195:5: note:   template argument deduction/substitution failed:
In file included from ./wsd/LOOLWebSocket.hpp:22:0,
                 from wsd/AdminModel.hpp:20,
                 from wsd/Admin.hpp:23,
                 from wsd/Admin.cpp:28:
./common/Protocol.hpp:268:93: note:   deduced conflicting types for parameter 'const _Tp' ('unsigned int' and 'long unsigned int')
  = getDelimiterPosition(message.data(), std::min(message.size(), 500UL), '\n');
                                                                       ^
In file included from /usr/include/c++/6.3.1/bits/char_traits.h:39:0,
                 from /usr/include/c++/6.3.1/string:40,
                 from /usr/include/c++/6.3.1/stdexcept:39,
                 from /usr/include/c++/6.3.1/array:39,
                 from /usr/include/c++/6.3.1/tuple:39,
                 from /usr/include/c++/6.3.1/mutex:38,
                 from wsd/Admin.cpp:13:
/usr/include/c++/6.3.1/bits/stl_algobase.h:243:5: note: candidate: template<class _Tp, class _Compare> const _Tp& std::min(const _Tp&, const _Tp&, _Compare)
     min(const _Tp& __a, const _Tp& __b, _Compare __comp)
     ^~~
/usr/include/c++/6.3.1/bits/stl_algobase.h:243:5: note:   template argument deduction/substitution failed:
In file included from ./wsd/LOOLWebSocket.hpp:22:0,
                 from wsd/AdminModel.hpp:20,
                 from wsd/Admin.hpp:23,
                 from wsd/Admin.cpp:28:
./common/Protocol.hpp:268:93: note:   deduced conflicting types for parameter 'const _Tp' ('unsigned int' and 'long unsigned int')
  = getDelimiterPosition(message.data(), std::min(message.size(), 500UL), '\n');
                                                                       ^
In file included from /usr/include/c++/6.3.1/algorithm:62:0,
                 from /opt/poco/include/Poco/String.h:26,
                 from /opt/poco/include/Poco/Net/NameValueCollection.h:24,
                 from /opt/poco/include/Poco/Net/MessageHeader.h:24,
                 from /opt/poco/include/Poco/Net/HTTPMessage.h:24,
                 from /opt/poco/include/Poco/Net/HTTPRequest.h:24,
                 from wsd/Admin.cpp:17:
/usr/include/c++/6.3.1/bits/stl_algo.h:3447:5: note: candidate: template<class _Tp> _Tp std::min(std::initializer_list<_Tp>)
     min(initializer_list<_Tp> __l)
     ^~~
/usr/include/c++/6.3.1/bits/stl_algo.h:3447:5: note:   template argument deduction/substitution failed:
In file included from ./wsd/LOOLWebSocket.hpp:22:0,
                 from wsd/AdminModel.hpp:20,
                 from wsd/Admin.hpp:23,
                 from wsd/Admin.cpp:28:
./common/Protocol.hpp:268:93: note:   mismatched types 'std::initializer_list<_Tp>' and 'unsigned int'
  = getDelimiterPosition(message.data(), std::min(message.size(), 500UL), '\n');
                                                                       ^
In file included from /usr/include/c++/6.3.1/algorithm:62:0,
                 from /opt/poco/include/Poco/String.h:26,
                 from /opt/poco/include/Poco/Net/NameValueCollection.h:24,
                 from /opt/poco/include/Poco/Net/MessageHeader.h:24,
                 from /opt/poco/include/Poco/Net/HTTPMessage.h:24,
                 from /opt/poco/include/Poco/Net/HTTPRequest.h:24,
                 from wsd/Admin.cpp:17:
/usr/include/c++/6.3.1/bits/stl_algo.h:3453:5: note: candidate: template<class _Tp, class _Compare> _Tp std::min(std::initializer_list<_Tp>, _Compare)
     min(initializer_list<_Tp> __l, _Compare __comp)
     ^~~
/usr/include/c++/6.3.1/bits/stl_algo.h:3453:5: note:   template argument deduction/substitution failed:
In file included from ./wsd/LOOLWebSocket.hpp:22:0,
                 from wsd/AdminModel.hpp:20,
                 from wsd/Admin.hpp:23,
                 from wsd/Admin.cpp:28:
./common/Protocol.hpp:268:93: note:   mismatched types 'std::initializer_list<_Tp>' and 'unsigned int'
  = getDelimiterPosition(message.data(), std::min(message.size(), 500UL), '\n');
                                                                       ^
wsd/Admin.cpp: In member function 'virtual void MemoryStatsTask::run()':
wsd/Admin.cpp:336:18: error: comparison between signed and unsigned integer expressions [-Werror=sign-compare]
     if (totalMem != _lastTotalMemory)
         ~~~~~~~~~^~~~~~~~~~~~~~~~~~~
cc1plus: all warnings being treated as errors
make[2]: *** [Makefile:1065: wsd/Admin.o] Error 1
make[2]: Leaving directory '/mnt/usbstick/lool_co_git'
make[1]: *** [Makefile:1524: all-recursive] Error 1
make[1]: Leaving directory '/mnt/usbsti

So, how it can be fixed?
Thanks in advance.

P.S. My note for clear is: I put all sources under /mnt/usbstick and trying to have all stuff under /opt; poco libs are under /opt/poco