While Not using Coverity Plugin:
Building in workspace C:\Program Files (x86)\Jenkins\jobs\Demo\workspace
Using master perforce client: coverity_demo_win
[workspace] $ "C:\Program Files\Perforce\p4.exe" -P 2724A1B5872D6C885C36A8633DEEEE3A workspace -o coverity_demo_win
'Don't update client' is set. Not saving the client changes.
Note: .repository directory in workspace (if exists) is skipped during clean.
Quickly cleaning workspace...
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Build succeeded.
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Time Elapsed 00:01:28.86

While Using Coverity Plugin:
Building in workspace C:\Program Files (x86)\Jenkins\jobs\Demo\workspace
Using master perforce client: coverity_demo_Win
[workspace] $ "C:\Program Files\Coverity\Coverity Static Analysis\bin\cov-build" --dir C:\Demo\coverity --instrument --encoding UTF-8 --enable-pch C:\Windows\Microsoft.NET\Framework\v4.0.30319\MSBuild.exe C:\demo\win32\vc10\demotest.sln /p:configuration=Release /p:platform=x64 /nr:false "C:\Program Files\Perforce\p4.exe" workspace -o coverity_demo_win

• • • Perforce client workspace 'coverity_demo_win' doesn't exist.
    • Please create it, or allow Jenkins to manage clients on it's own.
    • If the client name mentioned above is not what you expected,
    • check your 'Client name format for slaves' advanced config option.
      ERROR: Error accessing perforce workspace.
      Finished: FAILURE

Please note workspace "coverity_demo_win" does exist.
The error occur while coverity plugin is enable.
When Coverity plugin is disable Perforce were able to sync & build without any issue.

Coverity plugin interfere with perforce commands.