procd: zram for /tmp feature is missing CONFIG dependencies
Username: Henrique de Moraes Holschuh
Origin: https://bugs.openwrt.org/index.php?do=details&task_id=1631
The config help for CONFIG_PROCD_ZRAM_TMPFS is missing several dependencies, without which the feature will fail to work at runtime.
On LEDE-17.01, one must set:
CONFIG_PROCD_ZRAM_TMPFS=y
CONFIG_PACKAGE_kmod-zram=y
CONFIG_PACKAGE_kmod-fs-ext4=y
CONFIG_PACKAGE_e2fsprogs=y
as well as their dependencies, for the "use zram for /tmp" feature of procd to work.
Either CONFIG_PROCD_ZRAM_TMPFS needs to arrange for these dependencies to be force-enabled, or its help text needs to document the need for them. The ext4 ones are anything but obvious...
Apparently, this issue is still present in openwrt-18.06 and trunk.