We have a large solution (~200 projects) that is being built on an on-premise build agent (TFS 2015) and are seeing some random build failures at the msbuild step with an error like this:
C:\Program Files (x86)\Microsoft Visual
Studio\2019\BuildTools\MSBuild\Current\Bin\Microsoft.Common.CurrentVersion.targets
(4384, 5) Unable to copy file
"C:\Work\100\s\Code\packages\MSTest.TestFramework.2.1.1\lib\net45\Microsoft.VisualStudio.TestPlatform.TestFramework.Extensions.xml"
to
"..\bin\Debug\Microsoft.VisualStudio.TestPlatform.TestFramework.Extensions.xml".
Access to the path
'..\bin\Debug\Microsoft.VisualStudio.TestPlatform.TestFramework.Extensions.xml'
is denied.
The error seems to occur randomly and typically if we run the build again it completes without error. As this is a continuous integration build we'd like to resolve the problem so it only fails for legitimate reasons. Developers on the team are getting too used to seeing build failures and are starting to miss legitimate failures with tests not passing!
The file itself is not being held open by any other process before the build starts (we are performing a clean get so it does not exist prior to the build starting) or after the build completes (have logged on to the server after a failed build and confirmed it is not held open by anything) so it appears to be the build process itself that is transiently holding the file open. My assumption is that, as we have multiple test projects in the solution referencing the test framework and all projects are set to use a common output folder, when they are being built in parallel there is a race condition and one project being built is holding open/writing to the file at the same time another wants to copy the file over.
We don't want to disable parallel builds if possible as this will add a significant amount of time to the build process, which is already a lot longer than I'd like.
I had considered turning off the copy local option on all but one of the projects but the error is related to an XML file rather then the DLL file that is being referenced.
So my questions would be:
Is my assumption correct that this would be caused by parallel builds or is there another reason it might be happening?
Why are the XML files being copied to the output folder in the first place?
Can the copying of the XML files be suppressed in any way as I don't think we actually need them there?
If we are unable to suppress copying the XML files are there any alternative ways that we could stop the error from occurring?
Thanks in advance for any help/advice.
I have a Visual Studio solution with x projects. Each project has (post) build events consisting of two or more lines.
When the build events are executed, a locking problem occurs:
The specified task executable "cmd.exe" could not be run. The process cannot access the file 'D:\Users\<user>\AppData\Local\Temp\tmpff905f7a0bf94226b86296693df6861c.exec.cmd' because it is being used by another process.
I suspect that Visual Studio writes the multiple lines to the unique temporary file which should be executed by cmd.exe. I first suspected there was a conflict between parallel builds, but since each build seems to create a unique file, that cannot be the cause.
Anohter nice detail is that the file in question, is not deleted after the error. When I open it, it is empty.
So...
Why is there a conflict?
Why is it empty?
I think its a rather simple question but I couldn't really find an answer for it so I will ask it in case someone else might need it .
There are developers who in-order to copy all projects to bin folder set the bin folder path using the project output path property and there are developers who use the xcopy command in post build event.
What are the main reasons for it ?
Regards ,
James Roeiter
I think setting project output path is a better option. The reason is that in this case Visual Studio is in control: it takes care of cleaning up, replacing older files, deciding which files to copy... When using xcopy, Visual Studio just invokes blindly a batch file. It will run all the commands on the batch which will result in files being copied whether they were compiled or not. Also, if the compilation order of projects changes, or new projects are added or removed, the corresponding post-build actions need to be updated, resulting in extra steps.
I have a solution with several projects in it that executes many custom build steps. Some projects depend on other projects, but most of the build steps are independent of each other.
When building inside the VS 2010 IDE, I am getting errors like this:
error MSB6003: The specified task executable "cmd.exe" could not be run. The process cannot access the file 'C:\full\path\Debug\custombuild.write.1.tlog' because it is being used by another process
However, when I build the solution with MSBuild from the command line, all is well, and the log file writing does not seem to cause the same error.
Is this a known issue? Google has not been much help today...
The answer was hinted at in an MSBuild forum thread.
The custom build rule logs are written into the containing project's $(IntDir). We had multiple projects (with no real output being sent to IntDir) that all inadvertently shared the same IntDir value. Giving each project its own IntDir value eliminated the problem.
I have a Visual Studio project with about 60 C++ source files. I can do a build, and it completes without errors. But if I immediately hit F7 again, it always re-compiles about 50 of the source files. It doesn't re-compile all of the files, which is strange.
I have 'Enable minimal rebuild' (/Gm) set. Any ideas why it might be doing this?
None of the files have a Modified Date in the future.
Are any of your file dates in the future? This can occur if you changed time zones or changed the system clock time. Dates in the future will confuse the IDE and force a rebuild every time F7 or F5 is hit.
I've solved the same problem.
In my case compiler displayed warning, that /Zi option is required if /Gm is specified.
/Gm enables "minimum rebuild", which requires debug information in .pdb file. So, if you don't want to use .pdb, also disable minumum rebuild - it solved a problem in my case.
Most probably is a matter of dependencies.
Consider the following possibilities:
If you have custom build tools defined for some of the files in your solution, make sure that the output property contains the right file name(s). If the output of the build tool doesn't correspond to the one(s) specified in the output file names, the builder will rebuild that file.
If you have custom build events, check whether the output from those build events don't affect the dependencies of the files to be built.
I had problems when trying, at post-build, to copy or move some of the output files to a build folder. The post build operations that affect the timestamp of the ouput files of the build process will determine rebuild each time.
In my case of such effect (C++ via VS2005) it was on Release configuration only, and the Studio tells in the build output, that compiler option /Gm is ignored if /Zi - option is not set. After setting /Zi via
Configuration Properties -> C/C++ -> General -> Debug Information Format : Program Database (/Zi) ,
it was ok. But isn`t there something wrong, when the Release Configuration needs something about Debugging? Not yet clear to me!
Project Properties -> "C/C++" -> "Output Files" -> "Program Database File Name" option should not be empty. Set this option by selecting from drop-down box . The option will be set like this: $(IntDir)\vc90.pdb. And line ProgramDataBaseFileName="" will be removed from vcproj file.
Then only changed *.cpp files will be recompiled when you build the project or solution.
It seems that this problem can be caused by many things, but what fixed it for me was:
Closing Visual Studio
Manually deleting all bin and obj folders (Clean doesn't seem to do the trick)
Opening the solution and running Clean (I'm not sure if this is necessary, but I did it just in case...)
Building like normal
Note: This was for a C# program in Visual Studio 2010.
After a couple days of googling, I ended up with a solution to my problem.
I encountered this problem when I moved my projects to a new PC. I had checked several times the creation date of the files. These dates were up-to-date, however the modification dates were in the bast (kinda bizarre) even when I changed the files.
A simple update of the files resolved the problem.
I'm having the same problem, and it seems to be because I've turned browse information off. Properties->C/C++->Browse Info->Enable Browse Info->None. The only fix I've found is turning it back on. This is for an xbox 360 project, fwiw, my other projects don't have the problem.
A reason is if the 'date last modified' for one of the source file is set for some date in the future: it rebuilds, and then the source file is still later than the executable.
This problem with the dates can happen if the source file is located in a directory a remote machine (a network share), and/or may even happen if your machine's time isn't synchronised with the date of the machine which is running the server of your source version control system.
Check your project includes any .h header file that doesn't exist on disk. Always happens to me when I delete a header file I'm not actually including anywhere, but forget to delete it from my solution navigator in VS. Note: missing headers produce no errors during the build (when not #included anywhere).
Check your project's Program Database Filename setting. For some reason, if this is set to the name of a directory (such as "$(IntDir)\"), it can sometimes cause VS to rebuild your project every time, even if you're not generating PDB files (i.e. Debug Information Format is set to "Disabled").
This is a bug in VS2008; I have not yet reproduced it yet in VS2010, but my tests haven't been thorough, so I'm not confident saying that the behavior isn't present in VS2010.
What caused similar symptoms at me was:
I have several projects in a solution. There were .cpp files which were referenced (and therefore compiled) by >1 projects. Unfortunately Visual Studio creates .obj files with a very simple naming - it just replaces ".cpp" by ".obj". Creating wrapper .cpp-s with different named solved the problem.
I had something similar. Even though I did have pre and post build events, they weren't causing the issue. It turned out that I had a number of projects down the reference chain that had content files that were marked as "copy always" instead of "copy if newer" meaning that these projects were always considered "out of date". By changing all of these to "copy if newer", changes to my unit test project no longer forced a recompile of all of the other projects.
Disabling "minimal rebuild" (Configuration Properties > C/C++ > Code Generation) fixed it for me. The compiler even left a clue:
1>cl : Command line warning D9007 : '/Gm' requires '/Zi or /ZI'; option ignored
Although I must point out, the compiler did not ignore the option as it said.
In my case I changed system data time to previous date so it is rebuilding every time because of different time stamp of the files once changed to the current time its not rebuilding every time.
We have that here regularly:
delete all intermediate and output files by hand. The clean option in vstudio is sometimes not enough. From a fresh start do the complete build. If after a complete build vstudio still wants to recompile certain files it might be related to next bullet.
if in your vcxproj a header file is referenced which is not on disk, the project is also recompiled. You might check this by some hidden feature described on MSDN blogs or just touch (i.e. click on it to open) all header files in the project exploder and see if one does not exist on disk
Had the same problem. Solved by:
-delete output folder (obj,exe,all files)
-run cygwin
-cd project folder
-run "touch *", which reset file modify date/time
-build and enjoy problem fixed
There is similar issue with project rebuild.
Visual Studio does not recompile but re-links a project every time on F7 hit.
Fix is simple. Try to open in Editor all files included into project (from Solution Explorer double click on each file) and remove from solution those files which do not exist.