screencapture-fix

Why?

This script helps you fix a broken screencapture on an OCLP-patched MacBookPro8,1 (and probably some other systems around 2011 as well). See my blog for why this script was created.

Prerequisites

• macOS Sequoia (15.7.4 - 15.8.1) installed on a MacBook Pro (Model ID MacBookPro8,1) using OCLP 2.4.1, OCLP 2.5 or OCLP 2.5.1
• System Integrity Protection (SIP) disabled, as configured by OCLP
• a clean screencapture binary from macOS Sequoia 15.7.4 or later, see How to get a clean screencapture binary
• this script

How to get a clean screencapture binary

The screencapture binary on the affected Mac itself is the broken one, so you can't take it from there, not even when booted into Recovery Mode. There are two other ways to get a clean one: copy it from another Mac, or let the script extract it from a macOS Sequoia installer, e.g. from the USB stick that OCLP has created.

Copy it from another Mac

A clean screencapture is a universal binary (x86_64 arm64e), while the broken one contains x86_64 only. Because of that, any Mac running macOS Sequoia 15.7.4 or later will do, no matter if it has an Intel or an Apple Silicon CPU, as long as it is not affected by the problem. Ideally it runs the same macOS version as the Mac that you want to fix.

On the second Mac, open the Terminal and

1. check the macOS version

   % sw_vers -productVersion
   15.7.4
   

2. copy the binary to your Desktop

   % cp /usr/sbin/screencapture ~/Desktop/screencapture
   

3. make sure it is a universal binary that contains both x86_64 and arm64e

   % file ~/Desktop/screencapture
   /Users/you/Desktop/screencapture: Mach-O universal binary with 2 architectures: [x86_64:Mach-O 64-bit executable x86_64] [arm64e:Mach-O 64-bit executable arm64e]
   ...
   

4. compare its checksum with the ones listed in the FAQs

   % shasum -a 256 ~/Desktop/screencapture
   

5. transfer the file to the Mac that you want to fix, e.g. by USB stick, AirDrop or a network share. Store it next to screencapture-fix.sh (see below), and make sure it is named exactly screencapture: don't rename it, and don't leave it zipped. Alternatively, keep it wherever you like and pass it to the script with -p <file>.
6. let the script check the binary on the Mac that you want to fix

   % ./screencapture-fix.sh --check -p ./screencapture
   

Extract it from a macOS Sequoia installer

If you have installed Sequoia with OCLP, you probably still have the USB stick with the macOS installer that OCLP has created. The installer contains the entire system, including a clean screencapture. With the option --get, the script extracts the binary from the installer and saves it next to the script.

1. install the script
2. plug in the USB stick, it shows up as /Volumes/Install macOS Sequoia
3. run

   % ./screencapture-fix.sh --get "/Volumes/Install macOS Sequoia"
   Installer : /Volumes/Install macOS Sequoia/Install macOS Sequoia.app
   Mounting SharedSupport.dmg (read-only)
   Release   : macOS 15.8 (24H23)
   Searching for usr/sbin/screencapture, this can take several minutes ...
   Searching payload.036
   Found     : usr/sbin/screencapture in payload.036
   Binary    : /Users/you/screencapture-fix/screencapture
   Archs     : x86_64 arm64e
   ...
   Check passed.
   Install it with:
     sudo ./screencapture-fix.sh --install
   

Instead of the USB stick you can also pass an Install macOS Sequoia.app, e.g. one that has been downloaded to /Applications. The installer is mounted read-only, so it remains unchanged. Root is not required, and --get doesn't patch anything. It just extracts the binary and checks it the same way as --check -p does.

Use an installer of the same macOS version as the Mac that you want to fix. The script warns you if the versions differ.

How to install

Create a folder of your choice, and download the screencapture-fix.sh file from GitHub into it.

Shortcut:

% mkdir ~/screencapture-fix
% cd ~/screencapture-fix
% curl -Ls https://bit.ly/screencapture-fix > screencapture-fix.sh
% chmod +x screencapture-fix.sh

Then copy the clean screencapture binary into the same folder, or let the script extract it from a macOS Sequoia installer:

% ls
screencapture		screencapture-fix.sh

Usage

Caution

Use at your own risk. This script modifies system files located in /usr/sbin/. While this fix has been tested on MacBookPro8,1 running macOS Sequoia via OCLP, always ensure you have a current backup of your data before modifying system-level binaries. The author is not responsible for any system instability or data loss.

Without any option, the script shows its help, and whether a suitable binary is embedded in the script (see Advanced Usage). None of the options below except --install changes anything on your system, and only --install requires root.

Is my screencapture broken?

Find out whether a fix is necessary at all, e.g. after a fresh installation or after reapplying the OCLP root patches:

% ./screencapture-fix.sh --check

The script checks the installed /usr/sbin/screencapture and tells you whether it is broken.

Check the clean binary

Let the script check the clean binary before you install it:

% ./screencapture-fix.sh --check -p ./screencapture

This also works for the binary of the system on another volume, e.g. ./screencapture-fix.sh --check -p "/Volumes/Macintosh HD/usr/sbin/screencapture".

Apply the fix

If the check has passed, fix the broken screencapture on an OCLP patched MacBookPro8,1 by running

% sudo ./screencapture-fix.sh --install

The script replaces /usr/sbin/screencapture with the clean binary and reboots. It takes the clean binary from

1. the file given by -p <file>, e.g. sudo ./screencapture-fix.sh --install -p ~/Desktop/screencapture,
2. otherwise from the payload embedded in the script (see Advanced Usage),
3. otherwise from the file screencapture next to the script.

It refuses binaries which are not suitable (e.g. a broken x86_64-only binary) before it touches the system volume. Reapplying OCLP root patches in the future will likely overwrite the fix. Run the script as often as needed.

To see a description of the script and all available options (-i/--install, -c/--check, -g/--get <dir>, -x/--extract, -p/--payload <file>, -f/--force, -h/--help, -v/--version), run

% ./screencapture-fix.sh --help

Advanced Usage

You can also append the screencapture binary to the script as its payload to make a single file. Compressing the payload with bzip2 makes the file considerably smaller.

% { cat ./screencapture-fix.sh; bzip2 -c ./screencapture; } > ./screencapture-fix-with-payload.sh
% chmod +x ./screencapture-fix-with-payload.sh

An uncompressed payload (cat ./screencapture-fix.sh ./screencapture > ./screencapture-fix-with-payload.sh) works as well.

Run the script without any option to see whether the payload is suitable for your Mac:

% ./screencapture-fix-with-payload.sh
...
Payload   : clean screencapture from macOS 15.8
Install it with:
  sudo ./screencapture-fix-with-payload.sh --install

--install uses the payload unless you pass another binary with -p <file>. The payload is extracted to a temporary folder, which is removed when the script exits.

To get the payload back as a file, e.g. to check it separately, extract it with --extract:

% ./screencapture-fix-with-payload.sh --extract -p ~/Desktop/screencapture

-p sets the destination, which can also be a folder. Without -p, the file screencapture is created next to the script. An existing file is overwritten with --force only.

Warning

You should not publish the script with an embedded screencapture binary because that would violate Apple's license terms.

FAQs

Do I need a specific screencapture binary for my macOS?

The screencapture binary is the same from macOS 15.7.4 to 15.7.7.

e668501ed8406aebcc3572a9b349553a27d429d0acfe26a5b364c2290ea8013d  /usr/sbin/screencapture

The screencapture binary from macOS 15.8 is different.

15f8ae56fbbe2e51c8ccfd04406e47fc619bd78ec364489585757b2b09471e1b  /usr/sbin/screencapture

The script warns you if the checksum of your binary doesn't match your macOS version.

Does the script support multiple boot volumes?

Yes, just boot from the volume that you want to patch. The script identifies the booted one.

Troubleshooting

"zsh: permission denied: ./screencapture-fix.sh"

The script is not executable, because downloads don't keep the executable flag. Run chmod +x screencapture-fix.sh.

"No clean screencapture binary found."

--install found neither a payload embedded in the script nor a file called screencapture in the folder of the script, and no -p <file> has been given. Follow the steps in How to get a clean screencapture binary. If the script lists a file like screencapture copy or screencapture.zip, unzip or rename it to screencapture.

"This binary contains x86_64 only ... It looks like the broken binary ..."

The binary has been copied from an affected Mac, probably from the one that you want to fix. Take it from another Mac, see How to get a clean screencapture binary.

"The binary is identical to the installed /usr/sbin/screencapture."

The fix has already been applied. If you want to install the binary again anyway, run sudo ./screencapture-fix.sh --install --force.

"Extracting the payload failed."

The payload appended to the script is truncated or corrupted. Create the single file again as described in Advanced Usage.

"Expected exactly one "Install macOS *.app", but found 0 in ..."

--get expects either the folder that contains the installer (e.g. the root of the USB stick) or the installer app itself. Check the name of the USB stick in the Finder or with ls /Volumes.

"Not found: .../SharedSupport.dmg"

The installer app is an install stub only, which downloads the actual installer when it runs. Use the USB stick created by OCLP, or a full installer instead.

"Mounting /dev/... failed."

Reboot and try again. Make sure that SIP is disabled, as configured by OCLP.