Note: getting this on Xcode 4.3.2? Check out the answer to this question.
Note: creating a symbolic link to use the 4.2 lib seems to work fine
cd /Developer/Platforms/iPhoneOS.platform/DeviceSupport/4.2.1\ \(8C148\)/Symbols/
sudo ln -s ../../4.2\ \(8C134\)/Symbols/Developer
After upgrading from 4.2.0 (beta, I believe) to 4.2.1, the libXcodeDebuggerSupport.dylib file is missing, which results in:
warning: Unable to read symbols for /Developer/Platforms/iPhoneOS.platform/DeviceSupport/4.2.1 (8C148)/Symbols/Developer/usr/lib/libXcodeDebuggerSupport.dylib (file not found).
which I guess isn't good. Looking at the directory in question I note:
.../DeviceSupport/4.2 (8C134)/Symbols/Developer/usr/lib/libXcodeDebuggerSupport.dylib
but
.../DeviceSupport/4.2.1 (8C148)/Symbols/System/
.../DeviceSupport/4.2.1 (8C148)/Symbols/usr/
the above two dirs make up all the content in the 4.2.1 folder. No "Developer" folder. Checking the /usr/ dir there, I find no libXcodeDebuggerSupport.dylib file in the lib dir either, so ln -s'ing isn't an option.
Worth mentioning: after the upgrade, I plugged the iPad in and had to click "Use for development" in Xcode organizer. Doing so, I got a message about symbols missing for that version, and Xcode proceeded to generate such, then failed. I restored the iPad and did "Use for development" again, and nothing about missing symbols appeared...
Update: deletion of /Developer and reinstallation of Xcode from scratch does not fix this issue.
Update 2: I just realized that after the reinstall of Xcode,
.../DeviceSupport/4.2 (8C134)/Symbols
is now a symbolic link,
lrwxr-xr-x 1 root admin 36 Dec 3 17:17 Symbols -> ../../Developer/SDKs/iPhoneOS4.2.sdk
And the directory in question has the appropriate files. Maybe this is simply a matter of linking the 4.2.1 dir in the same fashion? I'll try that and see if Xcode freaks out. If someone who has this file could provide a md5 sum that would be splendid. This is what it says for me:
$ md5 /Developer/Platforms/iPhoneOS.platform/DeviceSupport/4.2\ \(8C134\)/Symbols/Developer/usr/lib/libXcodeDebuggerSupport.dylib
MD5 (/Developer/Platforms/iPhoneOS.platform/DeviceSupport/4.2 (8C134)/Symbols/Developer/usr/lib/libXcodeDebuggerSupport.dylib)
= 08f93a0a2e3b03feaae732691f112688
If the MD5 sum is identical to the output of
$ md5 /Developer/Platforms/iPhoneOS.platform/DeviceSupport/4.2.1\ \(8C148\)/Symbols/Developer/usr/lib/libXcodeDebuggerSupport.dylib
then we're all set.
What I just did to solve this problem was:
cd /Developer/Platforms/iPhoneOS.platform/DeviceSupport/4.2.1 (8C148)/Symbols
and created the symlink was missing:
ln -s ../../4.2\ \(8C134\)/Symbols/Developer/ Developer
It solves my problem.