Comment 17 for bug 1402195

It's not « Nexus 5 » specific issue.
Looking official android sdk documentation: ( https://developer.android.com/tools/help/adb.html#Enabling )
quote:
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Note: When you connect a device running Android 4.2.2 or higher to your computer, the system shows a dialog asking whether to accept an RSA key that allows debugging through this computer. This security mechanism protects user devices because it ensures that USB debugging and other adb commands cannot be executed unless you're able to unlock the device and acknowledge the dialog. This requires that you have adb version 1.0.31 (available with SDK Platform-tools r16.0.1 and higher) in order to debug on a device running Android 4.2.2 or higher.
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And obviously, android 5.+/5.1.1 seem to need this 1.0.32 version of adb.

I've an android 5.1.1, and need adb 1.0.32 to show my device (not a nexus)