If you ever get the message “Waiting for other installations to finish” while installing new software on OSX. You might have run into the case where a failed install is blocking the current install. iMovie has been notorious about doing this since I upgraded from Mountain Lion.

First look for an installation lock file. This will prevent any new installations even if there is no hung install process otherwise (if installs still hang after reboot this is probably the reason).

[tchen@evangelion] ~ ❯❯❯ ll /private/var/db/mds/system/mds.install.lock
-rw-r--r--  1 root  wheel     0B Dec 20 10:53 /private/var/db/mds/system/mds.install.lock
[tchen@evangelion] ~ ❯❯❯ sudo rm -rf /private/var/db/mds/system/mds.install.lock

In the above example I had one that was created by a failed install on 12/20. So go ahead and remove it.

Any stuck on waiting installs should immediately resume after that. If it does not then you need to find and kill the process that created that lock above.

[tchen@evangelion] ~ ❯❯❯ ps aux | grep install
root              522   0.2  1.7  2774812 278300   ??  Ss   Sun06PM   8:59.33 /System/Library/PrivateFrameworks/PackageKit.framework/Resources/installd
root            95018   0.0  0.3  3631240  44516   ??  S     9:33AM   0:02.44 /usr/sbin/installer -pkg /Users/tchen/Downloads/UnityPackages/Unity.pkg -target / -verboseR
root            94888   0.0  0.0  2440552   1116   ??  S     9:29AM   0:00.01 /bin/sh /Volumes/Unity Download Assistant/Unity Download Assistant.app/Contents/MacOS/installhelper.sh
root            26352   0.0  0.0  2500684   2428   ??  S    Mon05AM   0:00.03 /usr/bin/perl /private/var/folders/zz/zyxvpxvq6csfxvn_n0000000000000/C/PKInstallSandboxManager/4CA832EB-B66A-4107-BEE8-0177A82CFCDC.activeSandbox/Scripts/com.apple.pkg.iMovie_AppStore.R05ui7/postinstall_actions/updateHelpPost /var/folders/dj/9kqj7grx1pjcjfgscr3qgyqr0000gn/C/com.apple.appstore/408981434/fmq8245617896524060076.pkg / / / 0
root            26342   0.0  0.0  2446376   1716   ??  S    Mon05AM   0:00.01 /usr/bin/perl /var/folders/zz/zyxvpxvq6csfxvn_n0000000000000/C/PKInstallSandboxManager/4CA832EB-B66A-4107-BEE8-0177A82CFCDC.activeSandbox/Scripts/com.apple.pkg.iMovie_AppStore.R05ui7/postinstall /var/folders/dj/9kqj7grx1pjcjfgscr3qgyqr0000gn/C/com.apple.appstore/408981434/fmq8245617896524060076.pkg / / /
root            25869   0.0  0.2  2611504  30324   ??  Ss   Mon05AM   0:02.66 /System/Library/PrivateFrameworks/PackageKit.framework/Resources/system_installd
tchen           95737   0.0  0.0  2434836    780 s000  S+    9:45AM   0:00.00 grep --color=auto install

You can see from above that iMovie was the culprit this time. (You can verify this by matching the date that the file was created and when the process was running) Go ahead and kill the process(es) that were hanging.

[tchen@evangelion] ~ ❯❯❯ sudo kill -9 26352 26342 25869

Remember the pids above match MY processes. Replace them with any you find. This should clear it up. If it doesn’t feel free to drop me a msg.