osxhub

Dark terminal card headed A Mac has three names, showing scutil --get ComputerName returning a redacted friendly name with spaces and an apostrophe, scutil --get LocalHostName returning the hyphenated Bonjour version of it, and scutil --get HostName returning HostName: not set, with labels noting System Settings edits one of them and that the name values shown are redacted

How to Change Your Mac’s Hostname (and Why There Are Three)

by Marcus Reeve
November 8, 2026

Renaming a Mac looks like a one-field job, and for most people it is — two panes in System Settings cover it. The trouble starts when the old name keeps turning up afterwards: in the…

Dark terminal card headed The same error, both directions, showing lipo -archs on an Intel-only test binary returning x86_64, then arch -arm64 on that binary and arch -x86_64 on an arm64 binary both failing with arch: posix_spawnp: Bad CPU type in executable, with labels reading lipo -archs on the file and arch on the machine

“Bad CPU Type in Executable” on a Mac: What It Means and How to Fix It

by Marcus Reeve
November 2, 2026

A binary that runs fine on someone else’s Mac stops on yours with a single line: Bad CPU type in executable. It is not corruption and not a permissions problem. The file contains machine code…

Dark terminal card headed macOS does not ship tree, showing ls run against /usr/bin/tree, /bin/tree and /usr/sbin/tree with all three returning No such file or directory, and two labels reading brew install tree and or find piped to sed with nothing installed

The tree Command on macOS: How to Install It (and What to Use Instead)

by Marcus Reeve
October 30, 2026

You type tree in the Terminal and get zsh: command not found: tree. Nothing is wrong with your Mac — tree has never been part of macOS. It is a GPL utility from the Linux…

Dark terminal card showing the command file sample.plist bin.plist and its output, sample.plist identified as XML 1.0 document text ASCII text and bin.plist as Apple binary property list, under the heading Half your Mac's config files aren't text, with three labels reading plutil -p reads both, -extract Key raw for scripts, and -lint names the line

How to Read and Convert plist Files on macOS (plutil)

by Marcus Reeve
October 27, 2026

Property lists hold most of the configuration on a Mac — app preferences, launchd jobs, bundle Info.plist files, the OS version itself. Open one in a text editor and roughly half the time you get…

Dark terminal card headed Same command, three different errors, showing touch run against three paths: /osxhub-test returning Read-only file system, /System/Library/osxhub-test returning Operation not permitted, and /usr/local/osxhub-test returning Permission denied, with labels noting that / is mounted sealed and read-only and that there are 19 firmlinks to the data volume

“Read-only File System” on macOS: Why You Can’t Write to /

by Marcus Reeve
October 24, 2026

You try to drop a file at the top level of the disk, or a script tries to write into a system directory, and the shell says Read-only file system. Nothing is broken and nothing…

Dark terminal card headed Two switches, not one, showing csrutil status returning System Integrity Protection status enabled, csrutil authenticated-root status returning Authenticated Root status enabled, and csrutil disable refusing with the message that the tool needs to be executed from Recovery OS, plus labels noting man csrutil is 14 lines and names authenticated-root zero times

How to Disable System Integrity Protection (SIP) on a Mac

by Marcus Reeve
October 21, 2026

System Integrity Protection is the layer that stops even root from modifying system files, loading unsigned kernel extensions, or attaching a debugger to Apple’s own processes. Turning it off is a legitimate thing to do…

Output of pmset -g assertions showing PreventUserIdleSystemSleep held by the caffeinate command-line tool with the localized message THE CAFFEINATE TOOL IS PREVENTING SLEEP, and a second assertion held by powerd while the display is on

Mac Won’t Shut Down: How to Find What Is Blocking It

by Marcus Reeve
October 18, 2026

A Mac that will not shut down is almost always waiting for something rather than broken. macOS asks every running app to quit, and it will wait indefinitely for one that says no — or…

Terminal output of nvram -p listing variable names including auto-boot, boot-volume, SystemAudioVolume and prev-lang:kbd, next to nvram SystemAudioVolume returning %80 and boot-args returning a data was not found error

How to Reset NVRAM on a Mac (and Why Apple Silicon Has No Key Combination)

by Marcus Reeve
October 15, 2026

Advice to “reset the NVRAM” is everywhere, and on most Macs sold in the last few years the key combination it tells you to press does not exist. Apple’s own documentation is the clearest evidence:…

Three real SSH error lines stacked: Permission denied listing publickey, password and keyboard-interactive; Received disconnect port 22:2 Too many authentication failures; and the WARNING REMOTE HOST IDENTIFICATION HAS CHANGED banner

Common SSH Errors on macOS and What They Actually Mean

by Marcus Reeve
October 12, 2026

SSH errors are unusually good at pointing at the wrong thing. “Permission denied” reads like a password problem when it is usually a key problem, and “Too many authentication failures” sounds like you typed something……