[Haskell-cafe] STM: "nested atomically" error

Andrew Coppin andrewcoppin at btinternet.com
Thu Jan 12 22:50:22 CET 2012

On 12/01/2012 12:48 PM, Johan Brinch wrote:

> I'm not using any unsafe IO

OK, good...

> (only for debug printing)

...ah. It seems we have reached a contradiction.

> Where is a transaction being nested?

My guess is that your "debug printing" is causing something to be 
evaluated when it otherwise wouldn't be, causing a transaction to begin 
within a transaction.

I could, however, be horribly wrong about that...

More information about the Haskell-Cafe mailing list