Create custom partition confusion

Its working now, but …
what was confusing me is that my partition csv file was named
partition_custom but under the build directory is was partition.bin which made me
think it was not using the partition i created. It also makes a seperate spiffs.bin Which
now makes me think any time there is a spiffs partition there should be a file name
spiffs.bin

Below is the original post :
I am using the arduino framework with the espressif platform.
I am using file system spiffs. I have created a custom partition
by using the gen_esp32part.py script.

Here is my ini file
[env:esp32dev]
platform = espressif32
board = esp32dev
framework = arduino
monitor_speed = 115200
upload_protocol = esptool
upload_port = /dev/ttyUSB0
board_build.partitions = partitions_custom.csv
board_build.f_cpu = 160000000L
board_build.flash_mode = qio

I had to place both partition_custom.csv and
partition_custom.bin into my platformio …/partitions/ directory in order to
get partition_custom to be built into my build/esp32dev directory.
Is that the correct way? Because the docs say if you
want a custom partition table see expressifs docs which doesn’t jive
with platformio.

I thought if both csv and bin files were in the root of my project
that would take precedence. platformio.ino file was changed reflect
the change in partition used: board_build.partitions = partition_custom.csv

When I build the project I get a second partition file called spiffs.bin
I do not know where that is coming from (my project is named spiffs)
Please let me know why that happens.

Thanks for your help.