just to be sure

--HG--
branch : 0.9
extra : rebase_source : 0b6db190bcfcd43713abbe34129e0a48e2c076c7
properly catch errors and send HTTP 500, even in the development environment

--HG--
branch : 0.9
extra : rebase_source : a0bb267d7aee348e1571f725d5fb73ee4686ee5a