By looking at /var/log/system.log
just after the attempt to install the command line tools from within Xcode, here is the error message you get:
May 1 19:50:13 ••My_Mac•• Xcode[4711]: [MT] DVTAssertions: Warning in /SourceCache/IDEKit/IDEKit-2113/Framework/Classes/Downloadables/IDEDownloadablesActivityReporter.m:76
Details: Error Domain=PKInstallErrorDomain Code=102 "The package “BluetoothSDK.pkg” is untrusted." UserInfo=0x400c91e00 {NSLocalizedDescription=The package “BluetoothSDK.pkg” is untrusted., NSURL=file://localhost/private/var/folders/b5/1x0nn19j48l8x21shmcppq3m0000gn/T/attached-image-785d03d028219ec5426def5c3a84ea4de0c91e9e/Command%20Line%20Tools%20(Lion)/Packages/BluetoothSDK.pkg, PKInstallPackageIdentifier=com.apple.pkg.BluetoothSDKLeo, NSUnderlyingError=0x401ec3900 "The operation couldn’t be completed. CSSMERR_TP_CERT_EXPIRED"}
Object:
Method: +initialize
Thread: {name = (null), num = 1}
Please file a bug at http://bugreport.apple.com with this warning message and any useful information you can provide.
This error message means that the certificate signing BluetoothSDK.pkg
is expired.
An independant version of the Command line Tools may be downloaded from here:
Download for Apple Developers
by searching for "Command Line Tools (OS X Lion)" and selecting the last one (Apr 15, 2013):
