Qt static with MySQL issue

SGaist

Hi,

That's likely because you are linking to the dynamic version of libqmysqlclient.

Check that you really have a static version of the MySQL client library.

Cobra91151

Hi! You are right. I have updated the MySQL to mysql-5.7.23 and run a few tests, then commented the code:

#LIBS += -L"C:/MySQL/mysql-5.7.23-win32/lib" -llibmysql
#LIBS += -L"C:/MySQL/mysql-5.7.23-win32/lib" -lmysqlclient

I get the issue:
:-1: error: LNK1181: cannot open input file 'C:\MySQL\mysql-5.7.22-win32\lib\libmysql.lib'

This means that Qt uses the wrong MySQL lib (shared). It should use mysqlclient (static). So I need to reconfigure it with lib path to exactly point to the C:\MySQL\mysql-5.7.23-win32\lib\mysqlclient.lib static library or remove all the libs from the directory except for the mysqlclient.lib? Thanks.

SGaist

Are you sure C:\MySQL\mysql-5.7.23-win32\lib\mysqlclient.lib is a static library ? The .lib files can either be static libraries or import libraries.

Cobra91151

@SGaist

Yes, I know, it could be static/shared library. I don't know 100% this library is static. But from MySQL docs:

2.16.7. Compiling MySQL Clients on Windows
...
You can either link your code with the dynamic libmysql.lib library, which is just a wrapper to load in libmysql.dll on demand, or link with the static mysqlclient.lib library.

The MySQL client libraries are compiled as threaded libraries, so you should also compile your code to be multi-threaded.

It should be static. I will check it with Visual Studio 2017 static MFC test project.

SGaist

Are you looking at the latest version of the documentation ?

Cobra91151

@SGaist

So, you are right! I have checked the mysqlclient.lib using VS 2017 static MFC test project and I get the issues:

It means this library is a dynamic. So where to get the static library or source files to build this library as static? Thanks.

SGaist

MT and MD are just related to the Windows runtime type you'll be using.

Cobra91151

@SGaist

I have checked it using lib /list mysqlclient.lib and 7zip, it displayed:

This means the library is 100% static. So how to add it to Qt during reconfiguration? Should I provide full path to the library or remove all libs except mysqlclient.lib and provide path? Thanks.

SGaist

Can you show which configuration options you used ?

Cobra91151

@SGaist

Ok, my batch file:

SET /P qtBuildType=Qt build type (shared/static): 
SET /P qtBuildMySqlIncludePath=MySql include path: 
SET /P qtBuildMySqlLibPath=MySql lib path: 
SET /P qtBuildOpenSSLIncludePath=OpenSSL include path: 
SET /P qtBuildOpenSSLLibPath=OpenSSL lib path: 
SET /P qtBuildPath=Enter Qt build path: 
configure.bat -debug-and-release -%qtBuildType% -opensource -nomake tools -nomake examples -no-ltcg -sql-mysql -I "%qtBuildMySqlIncludePath%" -L "%qtBuildMySqlLibPath%" -ssl -openssl -openssl-linked -I "%qtBuildOpenSSLIncludePath%" -L "%qtBuildOpenSSLLibPath%" OPENSSL_LIBS="-lUser32 -lAdvapi32 -lGdi32 -lCrypt32" OPENSSL_LIBS_DEBUG="-lssleay32MTd -llibeay32MTd" OPENSSL_LIBS_RELEASE="-lssleay32MT -llibeay32MT" -prefix "%qtBuildPath%"

For example, MySql include path was : C:\MySQL\mysql-5.7.22-win32\include and MySql lib path C:\MySQL\mysql-5.7.22-win32\lib but it make Qt to use C:\MySQL\mysql-5.7.22-win32\lib\libmysql.lib (dynamic). I think, should be another way to set proper library.

SGaist

I would add MYSQL_LIBS=-lmysqlclient.

Cobra91151

@SGaist

Ok. I will try it and reply. Thanks.

Cobra91151

I added the MYSQL_LIBS="-lmysqlclient" to configure:

configure.bat -debug-and-release -%qtBuildType% -opensource -nomake tools -nomake examples -no-ltcg -sql-mysql -I "%qtBuildMySqlIncludePath%" -L "%qtBuildMySqlLibPath%" MYSQL_LIBS="-lmysqlclient" -ssl -openssl -openssl-linked -I "%qtBuildOpenSSLIncludePath%" -L "%qtBuildOpenSSLLibPath%" OPENSSL_LIBS="-lUser32 -lAdvapi32 -lGdi32 -lCrypt32" OPENSSL_LIBS_DEBUG="-lssleay32MTd -llibeay32MTd" OPENSSL_LIBS_RELEASE="-lssleay32MT -llibeay32MT" -prefix "%qtBuildPath%"

But I get the issue:

I think I should also provide the libmysql to MYSQL_LIBS or the problem is with mysql-5.7.23.

Cobra91151

I have found the issue! Adding this line MYSQL_LIBS="-lmysqlclient" to configure for some reason breaks the detection of MySQL. I will try again to confirm it.

Cobra91151

Yes, I was right. Adding MYSQL_LIBS="-lmysqlclient" breaks the detection of MySQL - 100% confirmed.

Cobra91151

I run a few tests and found that Qt requires libmysql.lib to configure, but since it dynamic lib it won't work in my case. I think I should try to rename mysqlclient.lib to libmysql.lib and test it.

Cobra91151

No, it fails with detection the MySQL if libmysql.lib has been changed, renamed or removed.

Cobra91151

I think I have found the issue.

This line of code in the file - configure.json - { "libs": "-lmysqlclient", "condition": "!config.win32" } disables mysqlclient (static) lib because condition states that !win32, means not Windows system. I will change it and try again.

Cobra91151

I have tried different solutions but it all failed.

The config.log:

+ cd /d D:\QtBuild\Src\config.tests\mysql && D:\QtBuild\Src\qtbase\bin\qmake.exe "CONFIG -= qt debug_and_release app_bundle lib_bundle" "CONFIG += static warn_off console single_arch" "QMAKE_LIBDIR += C:\\MySQL\\mysql-5.7.23-win32\\lib C:\\OpenSSL\\openssl-1.0.2l-vs2017\\lib" "INCLUDEPATH += C:\\MySQL\\mysql-5.7.23-win32\\include C:\\OpenSSL\\openssl-1.0.2l-vs2017\\include" "LIBS += -lmysqlclient" D:/QtBuild/Src/config.tests/mysql
+ cd /d D:\QtBuild\Src\config.tests\mysql && set MAKEFLAGS=& nmake
> Microsoft (R) Program Maintenance Utility Version 14.15.26726.0
> Copyright (C) Microsoft Corporation.  All rights reserved.
> 	cl -c -nologo -Zc:wchar_t -FS -Zc:rvalueCast -Zc:inline -Zc:strictStrings -Zc:throwingNew -Zc:referenceBinding -Zi -MDd -W0 -EHsc /Fdmysql.vc.pdb -DUNICODE -D_UNICODE -DWIN32 -I. -IC:\MySQL\mysql-5.7.23-win32\include -IC:\OpenSSL\openssl-1.0.2l-vs2017\include -ID:\QtBuild\Src\qtbase\mkspecs\win32-msvc -Fo @C:\Users\cobra\AppData\Local\Temp\nmC064.tmp
> main.cpp
> 	link /NOLOGO /DYNAMICBASE /NXCOMPAT /DEBUG /SUBSYSTEM:CONSOLE "/MANIFESTDEPENDENCY:type='win32' name='Microsoft.Windows.Common-Controls' version='6.0.0.0' publicKeyToken='6595b64144ccf1df' language='*' processorArchitecture='*'" /MANIFEST:embed /OUT:mysql.exe @C:\Users\cobra\AppData\Local\Temp\nmC2B7.tmp
> LINK : warning LNK4098: defaultlib 'MSVCRT' conflicts with use of other libs; use /NODEFAULTLIB:library
> mysqlclient.lib(xml.obj) : error LNK2001: unresolved external symbol __imp__sprintf
> mysqlclient.lib(libmysql.obj) : error LNK2001: unresolved external symbol __imp__sprintf
> mysqlclient.lib(my_time.obj) : error LNK2001: unresolved external symbol __imp__sprintf
> mysqlclient.lib(client.obj) : error LNK2001: unresolved external symbol __imp__sprintf
> mysqlclient.lib(ctype.obj) : error LNK2001: unresolved external symbol __imp__sprintf
> mysqlclient.lib(my_init.obj) : error LNK2019: unresolved external symbol __imp__RegCloseKey@4 referenced in function _win32_have_tcpip
> mysqlclient.lib(my_init.obj) : error LNK2019: unresolved external symbol __imp__RegEnumValueA@32 referenced in function _win_init_registry
> mysqlclient.lib(my_init.obj) : error LNK2019: unresolved external symbol __imp__RegOpenKeyExA@20 referenced in function _win32_have_tcpip
> mysqlclient.lib(my_default.obj) : error LNK2001: unresolved external symbol __imp____iob_func
> mysqlclient.lib(log_client.obj) : error LNK2001: unresolved external symbol __imp____iob_func
> mysqlclient.lib(my_init.obj) : error LNK2001: unresolved external symbol __imp____iob_func
> mysqlclient.lib(my_winfile.obj) : error LNK2001: unresolved external symbol __imp____iob_func
> mysqlclient.lib(my_mess.obj) : error LNK2001: unresolved external symbol __imp____iob_func
> mysqlclient.lib(typelib.obj) : error LNK2001: unresolved external symbol __imp____iob_func
> mysqlclient.lib(my_mess.obj) : error LNK2019: unresolved external symbol __imp__fprintf referenced in function _my_message_stderr
> mysqlclient.lib(typelib.obj) : error LNK2001: unresolved external symbol __imp__fprintf
> mysqlclient.lib(log_client.obj) : error LNK2001: unresolved external symbol __imp__fprintf
> mysqlclient.lib(client_authentication.obj) : error LNK2019: unresolved external symbol "__declspec(dllimport) char const * __cdecl std::_Winerror_map(int)" (__imp_?_Winerror_map@std@@YAPBDH@Z) referenced in function "public: virtual class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > __thiscall std::_System_error_category::message(int)const " (?message@_System_error_category@std@@UBE?AV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@2@H@Z)
> mysqlclient.lib(sha2_password_common.obj) : error LNK2001: unresolved external symbol "__declspec(dllimport) char const * __cdecl std::_Winerror_map(int)" (__imp_?_Winerror_map@std@@YAPBDH@Z)
> mysqlclient.lib(my_default.obj) : error LNK2019: unresolved external symbol __imp__printf referenced in function _my_load_defaults
> mysqlclient.lib(ssl.obj) : error LNK2019: unresolved external symbol __imp___snprintf referenced in function _ya_SSL_ASN1_TIME_to_string
> mysqlclient.lib(log_client.obj) : error LNK2019: unresolved external symbol __imp__vfprintf referenced in function "void __cdecl error_log_vprint(enum error_log_level::type,char const *,char *)" (?error_log_vprint@@YAXW4type@error_log_level@@PBDPAD@Z)
> mysqlclient.lib(common.obj) : error LNK2019: unresolved external symbol __imp__EqualSid@8 referenced in function "public: bool __thiscall Sid::operator==(class Sid const &)" (??8Sid@@QAE_NABV0@@Z)
> mysqlclient.lib(common.obj) : error LNK2019: unresolved external symbol __imp__GetTokenInformation@20 referenced in function "public: __thiscall Sid::Sid(void *)" (??0Sid@@QAE@PAX@Z)
> mysqlclient.lib(common.obj) : error LNK2019: unresolved external symbol __imp__IsValidSid@4 referenced in function "public: bool __thiscall Sid::is_valid(void)const " (?is_valid@Sid@@QBE_NXZ)
> mysqlclient.lib(common.obj) : error LNK2019: unresolved external symbol __imp__LookupAccountNameW@28 referenced in function "public: __thiscall Sid::Sid(wchar_t const *)" (??0Sid@@QAE@PB_W@Z)
> mysqlclient.lib(random.obj) : error LNK2019: unresolved external symbol __imp__CryptAcquireContextA@20 referenced in function "public: __thiscall TaoCrypt::OS_Seed::OS_Seed(void)" (??0OS_Seed@TaoCrypt@@QAE@XZ)
> mysqlclient.lib(random.obj) : error LNK2019: unresolved external symbol __imp__CryptReleaseContext@8 referenced in function "public: __thiscall TaoCrypt::OS_Seed::~OS_Seed(void)" (??1OS_Seed@TaoCrypt@@QAE@XZ)
> mysqlclient.lib(random.obj) : error LNK2019: unresolved external symbol __imp__CryptGenRandom@12 referenced in function "public: void __thiscall TaoCrypt::OS_Seed::GenerateSeed(unsigned char *,unsigned int)" (?GenerateSeed@OS_Seed@TaoCrypt@@QAEXPAEI@Z)
> mysql.exe : fatal error LNK1120: 17 unresolved externals
> NMAKE : fatal error U1077: '"C:\Program Files (x86)\Microsoft Visual Studio\2017\Enterprise\VC\Tools\MSVC\14.15.26726\bin\HostX86\x86\link.EXE"' : return code '0x460'
> Stop.
 => source failed verification.
Trying source 6 (type inline) of library mysql ...
+ cd /d D:\QtBuild\Src\config.tests\mysql && D:\QtBuild\Src\qtbase\bin\qmake.exe "CONFIG -= qt debug_and_release app_bundle lib_bundle" "CONFIG += static warn_off console single_arch" "QMAKE_LIBDIR += C:\\MySQL\\mysql-5.7.23-win32\\lib C:\\OpenSSL\\openssl-1.0.2l-vs2017\\lib" "INCLUDEPATH += C:\\MySQL\\mysql-5.7.23-win32\\include C:\\OpenSSL\\openssl-1.0.2l-vs2017\\include" "LIBS += -lmysqlclient" D:/QtBuild/Src/config.tests/mysql
+ cd /d D:\QtBuild\Src\config.tests\mysql && set MAKEFLAGS=& nmake clean && set MAKEFLAGS=& nmake
> Microsoft (R) Program Maintenance Utility Version 14.15.26726.0
> Copyright (C) Microsoft Corporation.  All rights reserved.
> 	del main.obj
> 	del mysql.vc.pdb mysql.ilk mysql.idb
> Microsoft (R) Program Maintenance Utility Version 14.15.26726.0
> Copyright (C) Microsoft Corporation.  All rights reserved.
> 	cl -c -nologo -Zc:wchar_t -FS -Zc:rvalueCast -Zc:inline -Zc:strictStrings -Zc:throwingNew -Zc:referenceBinding -Zi -MDd -W0 -EHsc /Fdmysql.vc.pdb -DUNICODE -D_UNICODE -DWIN32 -I. -IC:\MySQL\mysql-5.7.23-win32\include -IC:\OpenSSL\openssl-1.0.2l-vs2017\include -ID:\QtBuild\Src\qtbase\mkspecs\win32-msvc -Fo @C:\Users\cobra\AppData\Local\Temp\nmC3CF.tmp
> main.cpp
> 	link /NOLOGO /DYNAMICBASE /NXCOMPAT /DEBUG /SUBSYSTEM:CONSOLE "/MANIFESTDEPENDENCY:type='win32' name='Microsoft.Windows.Common-Controls' version='6.0.0.0' publicKeyToken='6595b64144ccf1df' language='*' processorArchitecture='*'" /MANIFEST:embed /OUT:mysql.exe @C:\Users\cobra\AppData\Local\Temp\nmC632.tmp
> LINK : warning LNK4098: defaultlib 'MSVCRT' conflicts with use of other libs; use /NODEFAULTLIB:library
> mysqlclient.lib(xml.obj) : error LNK2001: unresolved external symbol __imp__sprintf
> mysqlclient.lib(libmysql.obj) : error LNK2001: unresolved external symbol __imp__sprintf
> mysqlclient.lib(my_time.obj) : error LNK2001: unresolved external symbol __imp__sprintf
> mysqlclient.lib(client.obj) : error LNK2001: unresolved external symbol __imp__sprintf
> mysqlclient.lib(ctype.obj) : error LNK2001: unresolved external symbol __imp__sprintf
> mysqlclient.lib(my_init.obj) : error LNK2019: unresolved external symbol __imp__RegCloseKey@4 referenced in function _win32_have_tcpip
> mysqlclient.lib(my_init.obj) : error LNK2019: unresolved external symbol __imp__RegEnumValueA@32 referenced in function _win_init_registry
> mysqlclient.lib(my_init.obj) : error LNK2019: unresolved external symbol __imp__RegOpenKeyExA@20 referenced in function _win32_have_tcpip
> mysqlclient.lib(my_default.obj) : error LNK2001: unresolved external symbol __imp____iob_func
> mysqlclient.lib(log_client.obj) : error LNK2001: unresolved external symbol __imp____iob_func
> mysqlclient.lib(my_init.obj) : error LNK2001: unresolved external symbol __imp____iob_func
> mysqlclient.lib(my_winfile.obj) : error LNK2001: unresolved external symbol __imp____iob_func
> mysqlclient.lib(my_mess.obj) : error LNK2001: unresolved external symbol __imp____iob_func
> mysqlclient.lib(typelib.obj) : error LNK2001: unresolved external symbol __imp____iob_func
> mysqlclient.lib(my_mess.obj) : error LNK2019: unresolved external symbol __imp__fprintf referenced in function _my_message_stderr
> mysqlclient.lib(typelib.obj) : error LNK2001: unresolved external symbol __imp__fprintf
> mysqlclient.lib(log_client.obj) : error LNK2001: unresolved external symbol __imp__fprintf
> mysqlclient.lib(client_authentication.obj) : error LNK2019: unresolved external symbol "__declspec(dllimport) char const * __cdecl std::_Winerror_map(int)" (__imp_?_Winerror_map@std@@YAPBDH@Z) referenced in function "public: virtual class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > __thiscall std::_System_error_category::message(int)const " (?message@_System_error_category@std@@UBE?AV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@2@H@Z)
> mysqlclient.lib(sha2_password_common.obj) : error LNK2001: unresolved external symbol "__declspec(dllimport) char const * __cdecl std::_Winerror_map(int)" (__imp_?_Winerror_map@std@@YAPBDH@Z)
> mysqlclient.lib(my_default.obj) : error LNK2019: unresolved external symbol __imp__printf referenced in function _my_load_defaults
> mysqlclient.lib(ssl.obj) : error LNK2019: unresolved external symbol __imp___snprintf referenced in function _ya_SSL_ASN1_TIME_to_string
> mysqlclient.lib(log_client.obj) : error LNK2019: unresolved external symbol __imp__vfprintf referenced in function "void __cdecl error_log_vprint(enum error_log_level::type,char const *,char *)" (?error_log_vprint@@YAXW4type@error_log_level@@PBDPAD@Z)
> mysqlclient.lib(common.obj) : error LNK2019: unresolved external symbol __imp__EqualSid@8 referenced in function "public: bool __thiscall Sid::operator==(class Sid const &)" (??8Sid@@QAE_NABV0@@Z)
> mysqlclient.lib(common.obj) : error LNK2019: unresolved external symbol __imp__GetTokenInformation@20 referenced in function "public: __thiscall Sid::Sid(void *)" (??0Sid@@QAE@PAX@Z)
> mysqlclient.lib(common.obj) : error LNK2019: unresolved external symbol __imp__IsValidSid@4 referenced in function "public: bool __thiscall Sid::is_valid(void)const " (?is_valid@Sid@@QBE_NXZ)
> mysqlclient.lib(common.obj) : error LNK2019: unresolved external symbol __imp__LookupAccountNameW@28 referenced in function "public: __thiscall Sid::Sid(wchar_t const *)" (??0Sid@@QAE@PB_W@Z)
> mysqlclient.lib(random.obj) : error LNK2019: unresolved external symbol __imp__CryptAcquireContextA@20 referenced in function "public: __thiscall TaoCrypt::OS_Seed::OS_Seed(void)" (??0OS_Seed@TaoCrypt@@QAE@XZ)
> mysqlclient.lib(random.obj) : error LNK2019: unresolved external symbol __imp__CryptReleaseContext@8 referenced in function "public: __thiscall TaoCrypt::OS_Seed::~OS_Seed(void)" (??1OS_Seed@TaoCrypt@@QAE@XZ)
> mysqlclient.lib(random.obj) : error LNK2019: unresolved external symbol __imp__CryptGenRandom@12 referenced in function "public: void __thiscall TaoCrypt::OS_Seed::GenerateSeed(unsigned char *,unsigned int)" (?GenerateSeed@OS_Seed@TaoCrypt@@QAEXPAEI@Z)
> mysql.exe : fatal error LNK1120: 17 unresolved externals
> NMAKE : fatal error U1077: '"C:\Program Files (x86)\Microsoft Visual Studio\2017\Enterprise\VC\Tools\MSVC\14.15.26726\bin\HostX86\x86\link.EXE"' : return code '0x460'
> Stop.
 => source failed verification.
test config.sqldrivers.libraries.mysql FAILED
looking for library oci
Trying source 0 (type inline) of library oci ...
+ cd /d D:\QtBuild\Src\config.tests\oci && D:\QtBuild\Src\qtbase\bin\qmake.exe "CONFIG -= qt debug_and_release app_bundle lib_bundle" "CONFIG += static warn_off console single_arch" "QMAKE_LIBDIR += C:\\MySQL\\mysql-5.7.23-win32\\lib C:\\OpenSSL\\openssl-1.0.2l-vs2017\\lib" "INCLUDEPATH += C:\\MySQL\\mysql-5.7.23-win32\\include C:\\OpenSSL\\openssl-1.0.2l-vs2017\\include" "LIBS += -loci" D:/QtBuild/Src/config.tests/oci
+ cd /d D:\QtBuild\Src\config.tests\oci && set MAKEFLAGS=& nmake
> Microsoft (R) Program Maintenance Utility Version 14.15.26726.0
> Copyright (C) Microsoft Corporation.  All rights reserved.
> 	cl -c -nologo -Zc:wchar_t -FS -Zc:rvalueCast -Zc:inline -Zc:strictStrings -Zc:throwingNew -Zc:referenceBinding -Zi -MDd -W0 -EHsc /Fdoci.vc.pdb -DUNICODE -D_UNICODE -DWIN32 -I. -IC:\MySQL\mysql-5.7.23-win32\include -IC:\OpenSSL\openssl-1.0.2l-vs2017\include -ID:\QtBuild\Src\qtbase\mkspecs\win32-msvc -Fo @C:\Users\cobra\AppData\Local\Temp\nmC6EC.tmp
> main.cpp
> .\main.cpp(2): fatal error C1083: Cannot open include file: 'oci.h': No such file or directory
> NMAKE : fatal error U1077: '"C:\Program Files (x86)\Microsoft Visual Studio\2017\Enterprise\VC\Tools\MSVC\14.15.26726\bin\HostX86\x86\cl.EXE"' : return code '0x2'
> Stop.

Any ideas how to make it compile with the static library? Thanks.

Cobra91151

@SGaist said in Qt static with MySQL issue:

MT and MD are just related to the Windows runtime type you'll be using.

The issue must be with this. I checked Qt configure log and the same errors are displayed with MFC static test project in VS 2017.

alt text

LINK : warning LNK4098: defaultlib 'MSVCRT' conflicts with use of other libs; use /NODEFAULTLIB:library
1>mysqlclient.lib(xml.obj) : error LNK2001: unresolved external symbol __imp__sprintf
1>mysqlclient.lib(libmysql.obj) : error LNK2001: unresolved external symbol __imp__sprintf
1>mysqlclient.lib(my_time.obj) : error LNK2001: unresolved external symbol __imp__sprintf
1>mysqlclient.lib(client.obj) : error LNK2001: unresolved external symbol __imp__sprintf
1>mysqlclient.lib(ctype.obj) : error LNK2001: unresolved external symbol __imp__sprintf
1>mysqlclient.lib(my_error.obj) : error LNK2001: unresolved external symbol __imp__strcat_s
1>mysqlclient.lib(my_error.obj) : error LNK2001: unresolved external symbol __imp__strerror_s
1>mysqlclient.lib(my_init.obj) : error LNK2001: unresolved external symbol __imp__strdup
1>mysqlclient.lib(yassl_int.obj) : error LNK2001: unresolved external symbol __imp__strdup
1>OLDNAMES.lib(strdup.obi) : error LNK2001: unresolved external symbol __imp__strdup
1>mysqlclient.lib(my_default.obj) : error LNK2001: unresolved external symbol __imp____iob_func
1>mysqlclient.lib(log_client.obj) : error LNK2001: unresolved external symbol __imp____iob_func
1>mysqlclient.lib(my_init.obj) : error LNK2001: unresolved external symbol __imp____iob_func
1>mysqlclient.lib(my_winfile.obj) : error LNK2001: unresolved external symbol __imp____iob_func
1>mysqlclient.lib(my_mess.obj) : error LNK2001: unresolved external symbol __imp____iob_func
1>mysqlclient.lib(typelib.obj) : error LNK2001: unresolved external symbol __imp____iob_func
1>mysqlclient.lib(my_init.obj) : error LNK2001: unresolved external symbol __imp__putenv

It leads to Qt configure errors. For some reason it conflicts with MSVCRT lib.