pdftoppm: Add -layer option

6 jobs for layers in 4 minutes and 1 second (queued for 1 second)
latest
Status Job ID Name Coverage
  Build
passed #1192003
build

00:03:17

passed #1192008
build_android

00:02:49

passed #1192004
build_clang_libcpp

00:04:00

passed #1192007
build_clazy

00:03:04

passed #1192006
build_mingw64_fedora

00:02:45

passed #1192005
build_ubuntu_16_04

00:01:38