/etc/apt/apt.conf.d/90dpsyco is in dpsyco-base 1.0.36.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 | // All dpsyco packages should be updated after installation.
DPkg::Post-Invoke {"/usr/sbin/update-dpsyco || true";};
|