You could always get an external disk, and install the newer OS version on that to test whatever you want to test. If the only available interface is USB 2, that will be a performance problem (and may be problematic keeping the disk awake), but you probably can work around that, such as by having the big audio data files on your internal drive.
> On Apr 20, 2019, at 18:30, Greg Earle <ea...@isolar.dyndns.org> wrote: > > I've got a Mac mini running El Capitan 10.11.6. I've held the OS back > because I have a FireWire audio interface on it and FireWire is deprecated in > more recent OSes. > > I am having a problem with my Blu-ray player not recognizing NFS shares on > the same Mac mini. I went to install Wireshark to debug the NFS traffic but > it won't install because the current "qt5-qtbase" port is only for Sierra or > newer: > > -- > Mac-mini:~ admin$ sudo port install qt5-qtbase > ---> Computing dependencies for qt5-qtbase > ---> Fetching distfiles for qt5-qtbase > Error: qt5-qtbase requires macOS 10.12 or later > Error: Failed to fetch qt5-qtbase: incompatible OS version > Error: See > /opt/local/var/macports/logs/_private_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_aqua_qt5/qt5-qtbase/main.log > for details. > Error: Follow https://guide.macports.org/#project.tickets to report a bug. > Error: Processing of port qt5-qtbase failed > -- > > Is there any way to build/install an older Wireshark/Qt5 port combo that will > still work on El Capitan? > > My impression of MacPorts has always been that you can only build/install > whatever port happens to be installed after you last did a "port self > update". I can't really risk going to Sierra and have this audio interface > stop working. :-/ > > - Greg >
