The commit 1278 in Pigment for this bug changed the API, the signal PgmImage::pixbuf-loaded is now called PgmImage::file-loaded. You have to apply this attached patch.
The commit 1278 in Pigment for this bug changed the API, the signal PgmImage: :pixbuf- loaded is now called PgmImage: :file-loaded. You have to apply this attached patch.