Runtime issues on older versions of macOS

Very old versions of macOS may fail to run modern NetBeans (confirmed for 10.13 High Sierra).

Symptom: Immediate crash on launch (“Apache NetBeans 17 cannot be opened because of a problem”).

Looking at the crash log:

Termination Reason: DYLD, [0x1] Library missing

Application Specific Information:
dyld: launch, loading dependent libraries

Dyld Error Message:
Library not loaded: @rpath/libswiftCore.dylib
Referenced from: /Applications/NetBeans/Apache NetBeans 17.app/Contents/MacOS/netbeans
Reason: image not found

Cause: According to https://issues.apache.org/jira/browse/NETBEANS-5481 this is because NetBeans is compiled with a newer version of Xcode that inserts an incompatible Swift launcher wrapper (or something along those lines).

Solution: As suggested in this comment, download and install the Swift 5 runtime library from https://support.apple.com/kb/dl1998?locale=en_US.

Fix confirmed on 10.13 High Sierra. This will almost certainly stop working at some stage, but hopefully by then people will have upgraded…