docs: add toolchain issue
This commit adds how to resolve "arm-none-eabi-gcc: Command not found" error.
- [Board-Specific](#board-specific)
## Common
+The issues below are faced during the manual setup of build environment.
+
### Issues on Kconfig-frontend
#### Build break on hconf
If you are using gperf 3.1 and kconfig-frontends-4.11.0.1,
@@ -54,6 +56,24 @@ make
sudo make install
```
+### Issues with toolchain
+When ```make ``` executes, you may encounter below error:
+```
+arm-none-eabi-gcc: Command not found
+```
+This may happen if the toolchain path is not added to ```PATH```.
+To resolve:
+```
+export PATH=<Your Toolchain PATH>:$PATH
+```
+If toolchain path is added to ```PATH```, then this may be because the toolchain you
+set uses 32-bit libs on the 64-bit system. For this matter, install the below toolchain
+as alternative.
+To resolve:
+```
+> $ sudo apt-get install -y gcc-arm-none-eabi
+```
+
### Issue on build of Proto buffers
When Proto buffers (a.k.a., protobuf) which is mandatory on using gRPC is enabled,
you can meet build breaks as shown below:
