Question

I’ve a C++ project that I’m currently porting from VS2008 to VS2010. When I build the project, Visual Studio 2010 reports the build as successful but if I then press F5 to start the debugger I’m told that the project is not up to date. If I ignore this warning, I can continue debugging ok, but if I press ok, the whole project (many hundreds of source files), gets rebuilt from scratch. The output contains the following;

1>------ Build started: Project: SCCW-VC2010, Configuration: Debug Win32 ------
1>Build started 15/11/2010 14:47:40.
1>InitializeBuildStatus:
1>  Creating "Debug\SCCW-VC2010.unsuccessfulbuild" because "AlwaysCreate" was specified.
1>Midl:
1>  All outputs are up-to-date.
1>ClCompile:
1>  tinedit.cpp
1>  _WIN32_WINNT not defined. Defaulting to _WIN32_WINNT_MAXVER (see WinSDKVer.h)
1>  Automatically linking with sfl504d.lib
1>  Automatically linking with ot1104d.lib
1>c:\program files\rogue wave\stingray studio 10.4\include\toolkit\sectndlg.h(134): warning C4996: 'strcpy': This function or variable may be unsafe. Consider using strcpy_s instead. To disable deprecation, use _CRT_SECURE_NO_WARNINGS. See online help for details.
1>          c:\program files\microsoft visual studio 10.0\vc\include\string.h(105) : see declaration of 'strcpy'
1>  Automatically linking with og1204d.lib
1>  Automatically linking with RWUXThemeD10.lib
1>  profile.cpp
1>  ZOffsetDialog.cpp

Half an hour later, once the build is finished, the debugger starts. My guess is that the message

Creating "Debug\SCCW-VC2010.unsuccessfulbuild" because "AlwaysCreate" was specified.

is part of the problem, but I cant tie this to a project setting. I’ve found some help on google, but nothing that has worked thus far. Anyone else had this problem and know of a fix?

Edit: As per Jalf’s suggestion in the comments below, I have created a new projected, imported all my files into that project, and the new project has the same problems. Specifically, I copied over all the following groups;

<ClCompile Include="..\MyDir\MyFile.cpp"/>
<ClInclude Include="..\MyDir\MyFile.h" />
<None Include="res\MyFile.ico" />  (and all similar resources)
<Library Include="..\MyDir\MyFile.lib" />

Edit2: After going through all the header includes I eventually found 3 that did not exist. Removing them and doing a rebuild all on the original project seems to have fixed the problem. Some of the blog posts that mention this problem refer to it as a bug, and two days of lost time later, I tend to agree. Thanks for the answers and comments provided.

Edit3: And one day later the problem is back! Making any edit to any file in the project once again causes a full rebuild. As per John Dibling’s answer, the project does include some static libraries, including Stingray. I’m ditching VS2010 and moving back to VS2008, as I have deadlines. For related information, see the following links;

Visual Studio 2010 always thinks project is out of date, but nothing has changed

http://social.msdn.microsoft.com/Forums/en-US/vcgeneral/thread/38c08137-3bb0-4143-b97f-72d077646318

Link

Final Edit The release of VS2010 SP1 has solved this problem, and builds are now fast and efficient.

Answer 1

I’ve had this problem many times and it was always frustrating. I’ll tell you what the problem was in my case, but first I have to ask you:

• Did you do a rebuild-all before you tried running the first time, or just a rebuild?
• Once you do a rebuild all, does it ask you yet again to rebuild if you’ve made no changes?

The problem in my case was somewhat complex. I had custom build rules that copies binaries for Stingray from their source directory (where they lived) to a directory in my build tree. The binaries were marked as a dependancy, so that they were copied before each build in case they changed.

The dependancy checked looked at the timestamps of these files to see when they were changed. If the blah.lib had a mod date of last December in it’s source directory, then when it was copied it would have the same mod date. The dependancy checked would note that “hey this file’s pretty old, we have to rebuild it,” and then it would ask if I wanted to do a full rebuild.

For a while I got by by just saying “No,” but eventually I fixed the problem by changing the custom build rule to write a new text file after it did the file copy. That would make the new text file the dependancy, and not the blah.lib file, and it made the compiler happy.