Alright, here's the build log:
------ Build started: Project: dosbox, Configuration: Release Win32 ------
Compiling...
fpu.cpp
Generating Code...
Compiling...
dirent.c
Generating Code...
Compiling...
support.cpp
setup.cpp
\dosbox\dosbox\src\misc\setup.cpp(35) : warning C4244: '=' : conversion from 'double' to 'float', possible loss of data
programs.cpp
messages.cpp
shell_misc.cpp
shell_cmds.cpp
\dosbox\dosbox\src\shell\shell_cmds.cpp(617) : warning C4541: 'dynamic_cast' used on polymorphic type 'DOS_Drive' with /GR-; unpredictable behavior may result
shell_batch.cpp
shell.cpp
\dosbox\dosbox\src\shell\shell.cpp(122) : warning C4101: 'old_in' : unreferenced local variable
\dosbox\dosbox\src\shell\shell.cpp(122) : warning C4101: 'old_out' : unreferenced local variable
int10_vesa.cpp
\dosbox\dosbox\src\ints\int10_vesa.cpp(302) : warning C4244: 'argument' : conversion from 'Bit16u' to 'Bit8u', possible loss of data
int10_put_pixel.cpp
int10_pal.cpp
int10_modes.cpp
int10_misc.cpp
int10_memory.cpp
int10_char.cpp
\dosbox\dosbox\src\ints\int10_char.cpp(503) : warning C4800: 'int' : forcing value to bool 'true' or 'false' (performance warning)
int10.cpp
xms.cpp
mouse.cpp
ems.cpp
dpmi.cpp
Generating Code...
Compiling...
bios_keyboard.cpp
bios_disk.cpp
bios.cpp
sdlmain.cpp
../include\sdl.h(33) : fatal error C1083: Cannot open include file: 'SDL_main.h': No such file or directory
render.cpp
../include\png.h(329) : fatal error C1083: Cannot open include file: 'zlib.h': No such file or directory
midi.cpp
tandy_sound.cpp
sblaster.cpp
pcspeaker.cpp
../include\sdl.h(33) : fatal error C1083: Cannot open include file: 'SDL_main.h': No such file or directory
mpu401.cpp
gus.cpp
\dosbox\dosbox\src\hardware\gus.cpp(578) : warning C4244: 'return' : conversion from 'Bit32u' to 'Bit16u', possible loss of data
\dosbox\dosbox\src\hardware\gus.cpp(582) : warning C4244: 'return' : conversion from 'Bit32u' to 'Bit16u', possible loss of data
\dosbox\dosbox\src\hardware\gus.cpp(586) : warning C4244: 'return' : conversion from 'Bit32s' to 'Bit16u', possible loss of data
\dosbox\dosbox\src\hardware\gus.cpp(590) : warning C4244: 'return' : conversion from 'Bit32u' to 'Bit16u', possible loss of data
\dosbox\dosbox\src\hardware\gus.cpp(595) : warning C4244: 'return' : conversion from 'Bit32u' to 'Bit16u', possible loss of data
\dosbox\dosbox\src\hardware\gus.cpp(715) : warning C4244: '=' : conversion from 'double' to 'float', possible loss of data
\dosbox\dosbox\src\hardware\gus.cpp(813) : warning C4244: 'return' : conversion from 'Bit16u' to 'Bit8u', possible loss of data
\dosbox\dosbox\src\hardware\gus.cpp(954) : warning C4018: '<' : signed/unsigned mismatch
\dosbox\dosbox\src\hardware\gus.cpp(995) : warning C4018: '<' : signed/unsigned mismatch
\dosbox\dosbox\src\hardware\gus.cpp(1008) : warning C4244: '=' : conversion from 'double' to 'float', possible loss of data
\dosbox\dosbox\src\hardware\gus.cpp(1016) : warning C4244: '=' : conversion from 'double' to 'float', possible loss of data
gameblaster.cpp
disney.cpp
adlib.cpp
vga_seq.cpp
vga_misc.cpp
vga_memory.cpp
vga_gfx.cpp
vga_draw.cpp
\dosbox\dosbox\src\hardware\vga_draw.cpp(118) : warning C4018: '<' : signed/unsigned mismatch
vga_dac.cpp
Generating Code...
Compiling...
vga_crtc.cpp
vga_attr.cpp
vga.cpp
../include\sdl.h(33) : fatal error C1083: Cannot open include file: 'SDL_main.h': No such file or directory
ipxserver.cpp
c:\dosbox\dosbox\include\sdl.h(33) : fatal error C1083: Cannot open include file: 'SDL_main.h': No such file or directory
ipx.cpp
c:\dosbox\dosbox\include\sdl.h(33) : fatal error C1083: Cannot open include file: 'SDL_main.h': No such file or directory
timer.cpp
../include\sdl.h(33) : fatal error C1083: Cannot open include file: 'SDL_main.h': No such file or directory
softmodem.cpp
c:\dosbox\dosbox\include\sdl.h(33) : fatal error C1083: Cannot open include file: 'SDL_main.h': No such file or directory
serialport.cpp
../include\sdl.h(33) : fatal error C1083: Cannot open include file: 'SDL_main.h': No such file or directory
pic.cpp
../include\sdl.h(33) : fatal error C1083: Cannot open include file: 'SDL_main.h': No such file or directory
mixer.cpp
../include\sdl.h(33) : fatal error C1083: Cannot open include file: 'SDL_main.h': No such file or directory
memory.cpp
keyboard.cpp
joystick.cpp
iohandler.cpp
hardware.cpp
dma.cpp
cmos.cpp
../include\sdl.h(33) : fatal error C1083: Cannot open include file: 'SDL_main.h': No such file or directory
drives.cpp
drive_virtual.cpp
drive_local.cpp
Generating Code...
Compiling...
drive_cache.cpp
\dosbox\dosbox\src\dos\drive_cache.cpp(202) : warning C4018: '<=' : signed/unsigned mismatch
\dosbox\dosbox\src\dos\drive_cache.cpp(326) : warning C4018: '<' : signed/unsigned mismatch
dos_tables.cpp
dos_programs.cpp
../include\sdl.h(33) : fatal error C1083: Cannot open include file: 'SDL_main.h': No such file or directory
dos_mscdex.cpp
../include\sdl.h(33) : fatal error C1083: Cannot open include file: 'SDL_main.h': No such file or directory
dos_misc.cpp
dos_memory.cpp
dos_ioctl.cpp
dos_files.cpp
dos_execute.cpp
dos_devices.cpp
dos_classes.cpp
dos.cpp
cdrom_ioctl_win32.cpp
../include\sdl.h(33) : fatal error C1083: Cannot open include file: 'SDL_main.h': No such file or directory
cdrom_aspi_win32.cpp
../include\sdl.h(33) : fatal error C1083: Cannot open include file: 'SDL_main.h': No such file or directory
cdrom.cpp
../include\sdl.h(33) : fatal error C1083: Cannot open include file: 'SDL_main.h': No such file or directory
debug_win32.cpp
debug_gui.cpp
../include\curses.h(38) : fatal error C1083: Cannot open include file: 'sys/cdefs.h': No such file or directory
debug_disasm.cpp
debug.cpp
../include\curses.h(38) : fatal error C1083: Cannot open include file: 'sys/cdefs.h': No such file or directory
paging.cpp
Generating Code...
Compiling...
modrm.cpp
flags.cpp
cpu.cpp
\dosbox\dosbox\src\cpu\cpu.cpp(715) : warning C4554: '&' : check operator precedence for possible error; use parentheses to clarify precedence
\dosbox\dosbox\src\cpu\cpu.cpp(723) : warning C4554: '&' : check operator precedence for possible error; use parentheses to clarify precedence
\dosbox\dosbox\src\cpu\cpu.cpp(741) : warning C4102: 'call_gate_same_privilege' : unreferenced label
core_normal.cpp
core_full.cpp
\dosbox\dosbox\src\cpu\core_full.cpp(106) : warning C4102: 'exit_core' : unreferenced label
core_dyn_x86.cpp
c:\dosbox\dosbox\src\cpu\core_dyn_x86\risc_x86.h(157) : warning C4018: '<' : signed/unsigned mismatch
c:\dosbox\dosbox\src\cpu\core_dyn_x86\risc_x86.h(174) : warning C4018: '<' : signed/unsigned mismatch
callback.cpp
dosbox.cpp
../include\sdl.h(33) : fatal error C1083: Cannot open include file: 'SDL_main.h': No such file or directory
Generating Code...
c:\dosbox\dosbox\src\cpu\core_dyn_x86\risc_x86.h(112) : warning C4731: 'gen_runcode' : frame pointer register 'ebp' modified by inline assembly code
c:\dosbox\dosbox\src\cpu\core_dyn_x86.cpp(225) : warning C4731: 'CPU_Core_Dyn_X86_Run' : frame pointer register 'ebp' modified by inline assembly code
Build log was saved at "file://c:\dosbox\dosbox\visualc_net\Release\BuildLog.htm"
dosbox - 20 error(s), 28 warning(s)
---------------------- Done ----------------------
Build: 0 succeeded, 1 failed, 0 skipped