Sorry for the relatively late post, but I've found that this build introduced a bug not found in 4446 and earlier, and remains in later builds after 4454.
I'm using a batch file to define an environment variable %IDEDIR%, and then run Code::Blocks (that's to make Code::Blocks portable). Then I use %IDEDIR% to define include/lib folders by defining $(#ideenv) global variable as %IDEDIR%.
In 4446 and earlier that worked. E.g. when I right-clicked an #include statement and clicked to open that file, it opened it. Now in 4454 it says not found - same thing as if I ran Code::Blocks without the batch to define %IDEDIR%. I should note that it only happens when I open a project's cbp file, when I open the project through Code::Blocks, it works.
Since that might be important, here's the batch I use as a loader for Code::Blocks (it differentiates between running Code:Blocks or opening a cbp, but before 4454 that worked). The batch's StartCB.bat, and it's in the same directory as codeblocks.exe (so %~dp0 would be Code::Blocks' directory).
@echo off
set cbdir=%~dp0
pushd %cbdir%
cd ..
set IDEDIR=%cd%
popd
if not (%1)==() goto HasParam
goto EndHasParam
:HasParam
set filedir=%~dp1
start %cbdir%codeblocks.exe %filedir%%~n1%~x1
goto :EOF
:EndHasParam
start %cbdir%codeblocks.exe
