Arduino IDE error when compiling

I hope I m in the right forum here for this question but if not please direct me to the correct one.
I have been trying unsuccesfully to compile the github downloaded Marlin Anet firmware. I keep getting an error and cant see from the error messages what my problem is probably because I am very new to reading the problem and understanding what it is saying.

I am hoping someone on here can give me some ideas to pursue so I can compile then save a hex ffile of the compiled sketch so I can use it to flash my Anet A8 Marlin firmware.

Thank you in advance for any help. I have attached the error message.

AnetCompile error.txt (636 KB)

Hi, I don't know the Marlin project, but it seems that a Arduino Mega needs to be selected.

You get a "Oops! Select 'Arduino/Genuino Mega or Mega 2560' in 'Tools > Board.'" warning, that is not from the compiler but it comes from the file "pins_RAMPS.h".
That causes an avalanche of errors, because certain pin definitions can not be found.

Are you replacing the ANET A8 controller board with a RAMPS board? If not, you have to install, and select, the Arduino core for the ATmega1284p (Sanguino) processor.

Hello Koepel and Johnwasser. My sincere apologies for not responding earlier to your helpful comments after I posted my problem. Asking a question and seeking help then not responding when it is given is very poor form and and while our local Covid responses had an impact on my time it is still not good to not respond.

An update on my problem now I have had a chance to revisit is that I am no closer to solving my problem. I have again posted the error message received and can advise the following.
I have the Anet board definitions installed and Arduino is accessing them and I am choosing the Anet V1.0(optiboot) option
I have completely reinstalled my Arduino software and cleaned up some previous installations that seemed to have been interfering with the program.
I have downloaded and am using the Marlin 2.0 sketch
My board is a MEGA 1284P and I access my printer via Octopi but that is not an issue as i am unable to create a compiled hex file using Arduino that I can even send to the printer.

Not sure if any other items might be useful to know but do hope you both will forgive my bad manners and perhaps offer a suggestion for how I can create a useable hex file

Regards and thank you in advance

Arduino Anet Compile failure 20 July 2020.txt (662 KB)

A quick update and follow on from my previous post. Following on from Koepel’s suggestion I tried compiling the same sketch using a Arduino mega board definition and setting the processor to AT Mega1280. Not the same as my processor I realise but interestingly the sketch compiled just fine which indicates to me my downloaded board definitions are not acceptable. To install the boards I copied the decompressed Anet file to the Arduini/hardware directory in Documents under my User name. Arduino found those definitions but I obviously haven’t “installed” them just given access to them. Could that be the problem or do I just have the wrong board definitions??