"No value to remove at key path MinimumSDKVersion"

[arekkusu42]

Using OSX 10.9.5 and starting with Xcode 6.2:

• I downloaded the linked Xcode3 and 4 installers
• I ran "./XcodeLegacy.sh -compilers -osx104 buildpackages" which appears to successfully extract all the components
• I ran "sudo ./XcodeLegacy.sh -compilers -osx104 install" which mostly succeeds, but produces this error near the end:

*** Info: found Xcode >= 4.3 in /Applications/Xcode.app
*** installed XcodePluginGCC40.tar.gz
(...)
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/powerpc-apple-darwin10-gcc-4.2.1 exists
* creating link /usr/bin/powerpc-apple-darwin10-gcc-4.2.1
* creating link /Applications/Xcode.app/Contents/Developer/usr/bin/powerpc-apple-darwin10-gcc-4.2.1
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Info.plist-original: Could not modify plist, error: No value to remove at key path MinimumSDKVersion
*** modified MacOSX Info.plist

and the resulting install is broken (it contains Info.plist-original, but no Info.plist)
...the XcodeLegacy.sh comment says "# Xcode >= 7.3 disables support..." but the logic modifying Info.plist isn't protected for installing into Xcode >= 7.3 ... :(