Support debugger on armLinux

Add the linux.aarch64 SWT jar from here:
https://repo1.maven.org/maven2/org/eclipse/platform/org.eclipse.swt.gtk.linux.aarch64/3.122.0/. Update the SWT jar-picking logic in the build to select this one
if the platform is `aarch64`. This is inconsistent with M1/2 Macs, where the
value is `arm`.

Note that I don't yet see a built copy for windows.aarch64. Would have loved to
kill two birds with one stone, but that must wait, it seems. Latest built of SWT
doesn't have it, either.

Improve building documentation where pitfalls were found while testing on ARM Ubuntu.

.github/workflows/build.yml

@@ -2,7 +2,7 @@
 # depends on pre-installed software; see image definitions:
 #  - https://github.com/actions/runner-images/blob/main/images/linux/Ubuntu2004-Readme.md
 #  - https://github.com/actions/runner-images/blob/main/images/macos/macos-12-Readme.md
-# We use these tools from the runner images: git, gcc/XCode/MSVC, swig, Tcl/Tk on MacOS
+# We use these tools from the runner images: git, gcc/XCode/MSVC, swig, Tcl/Tk on MacOS, pkg-config
 
 # TODO: not building svs_viewer ('Cannot find GL, GLU, not building svs_viewer' and 'Cannot find opengl32, glu32, not building svs_viewer')
 # TODO: pin more dependency versions (python, swig, gcc/XCode/MSVC, etc.)

Java/Debugger/SConscript

@@ -14,19 +14,21 @@ depjars = [
 def get_swt_path():
     swt_intel_jars = {
         ('linux', 32) : 'gtk32',
-        ('linux', 64) : 'gtk64',
+        ('linux', 64) : 'gtk64/i386',
         ('linux2', 32) : 'gtk32',
-        ('linux2', 64) : 'gtk64',
+        ('linux2', 64) : 'gtk64/i386',
         ('darwin', 32) : 'osx32',
         ('darwin', 64) : 'osx64/i386',
         ('win32',  32) : 'win32',
         ('win32',  64) : 'win64',
     }
     swt_arm_jars = {
         ('darwin', 64) : 'osx64/arm',
+        ('linux', 64) : 'gtk64/arm',
     }
 
-    if platform.processor() == 'arm':
+    # ARM processor returns 'arm' on Macs, 'aarh64' on Linux
+    if platform.processor() in ['arm', 'aarch64']:
         return swt_arm_jars[(sys.platform, 64 if '64' in platform.machine() else 32)]
     else:
         return swt_intel_jars[(sys.platform, 64 if '64' in platform.machine() else 32)]

README.md

@@ -7,7 +7,7 @@ This is the code base for Soar, a cognitive architecture for developing systems
 * [The Soar home page](http://soar.eecs.umich.edu/)
 * [The GitHub project page](https://github.com/SoarGroup/Soar)
 
-Note that the readme included with the Soar distribution for endusers is in the [Release-Support](https://github.com/SoarGroup/Release-Support/blob/master/txt/README) repository.
+Note that the readme included with the Soar distribution for end-users is in the [Release-Support](https://github.com/SoarGroup/Release-Support/blob/master/txt/README) repository.
 
 # Soar Builds
 
@@ -30,7 +30,7 @@ Disclaimer: These are worst case tests.  Average performance is probably much hi
 
 The instructions below are cursory and may be out of date; the most up-to-date instructions for compiling Soar from source will always be the CI build scripts. You can find them [here](.github/workflows/build.yml).
 
-To compile Soar, you will need the following:
+To compile Soar, you will need the dependencies listed below. Note that the installation commands are not complete, e.g. missing instructions for Mac do not mean that the dependency is not needed on Mac, etc.:
 
 * C/C++ compiler
     - Mac: `xcode-select --install`
@@ -42,9 +42,17 @@ To compile Soar, you will need the following:
 
 To compile the extra SML wrapper libs, you will need the following:
 
-* C# compiler (`csc`)
+* pkg-config
+    - Mac: `brew install pkg-config`
+    - Linux: `sudo apt install pkgconf`
+* SWIG
+    - Mac: `brew install swig`
+    - Linux: `sudo apt install swig`
+* Python development headers (only needed for Python wrapper)
+    - Linux: `sudo apt install python3-dev`
+* C# compiler (`csc`) (only needed for C# wrapper)
     - Mac: `brew install mono`
-* Tcl
+* Tcl (only needed for Tcl wrapper and TclSoarlib)
     - Mac: `brew install tcl-tk`
 
 The project supports generating compile_commands.json, which can be used by e.g. VSCode with the C/C++ plugin to provide IntelliSense. To generate this file, run scons with the `cdb` target: