Mac OS: - "can't be opened because it is from an unidentified developer"

Due to Canopy's multi-package multi-source architecture, Apple's application requirements prevent us from signing our Canopy application with a single identified developer ID. Canopy includes various forms of executable content such as package eggs and libraries, and our understanding is that Apple's policies prohibit adding this type of content to the application. This may change in the future, but in the meantime we recommend taking a look at this useful description of how to temporarily disable Apple's Gatekeeper in order to install a program, like Canopy, that is not from the Apple Store:

Note: With the release of macOS Sierra (macOS 10.12), Apple no longer provides the option to allow applications from "Anywhere", but instead restricts the options to allow opening of applications from only the App store or App store and Identified developers. Thus there is no longer a UI option to permanently disable Gatekeeper and allow opening of applications from unidentified developers. However, there are still a number of options to work around this problem:

A) After attempting to open an application from an unidentified developer, you will be prompted with a dialog telling you that you the application was blocked by the Gatekeeper system. Immediately after closing this dialog, you can open System Preferences and then select Security and Privacy. From the Security and Privacy pane, the bottom of the window should show you a similar message stating that an application was blocked by Gatekeeper due to being from an unidentified developer. Here there should be an "Open anyway" button, which will allow the application to open.

B) Another method is to drag Canopy from the Applications folder to the Dock, then open Canopy from the Dock icon by right-clicking, then selecting "Open" while holding down the Shift key.

C) If the above solutions are unable to address the issue, then you can temporarily disable the macOS Security Policy Assessment Subsystem before opening Canopy, then reenable the system after Canopy has been opened.

Note: the following code requires administrator privileges.

  1. Open
  2. Execute the following from Terminal:
    sudo spctl --master-disable
  3. Open ---> You may still be warned that this application is from an unidentified developer. If this is the case, try to open a second time. This time you should be given the option to cancel or "Open".
  4. Execute the following from Terminal (It is imperative to re-enable the security system):
    sudo spctl --master-enable

D) If the above does not work, you may try manually adding a security exception to the macOS security policy database:

sudo spctl --add -v /Applications/
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  • Avatar
    Shannon Jacobs

    Uh... How can I right click without a mouse? Actually, I borrowed a mouse to try it, but it would still be much better if there were some way to tell the Mac that Canopy is a properly signed and recognized developer... (Probably some mouse-less right-click equivalent exists, too? I should have tried an attack from that angle...)

  • Avatar
    Robin Dunn
    Pressing the Control key while clicking the left (or only) mouse button is equivalent on Macs to clicking the right mouse button.
  • Avatar
    Jonathan March

    Updated with a method that uses simple terminal commands.

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