On a sunny day and with a tall enough stick, it should be dead-on. At local apparent noon, the stick's shortest shadow should be pointed straight to true north. Given a long enough timeframe to lay out a line of stakes, the line should form a straight E-W line.

Do this as a test when you still have a compass to check it, this will give you the confidence to trust it. Personally, I would use this technique to check the compass, rather than using a compass to check the sun. Don't forget to account for magnetic deviation -- the sun compass is True.
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Better is the Enemy of Good Enough.
Okay, what’s your point??