Eclipse Plugin, SWT "Unresolved requirement: Require-Capability" - eclipse-plugin

Question

I'm stuck. I am unable to figure out what is causing me to receive "Unresolved requirement: Require-Capability" errors for an SWT bundle (and others, if I dig deeper). The requirements stated for it are win32 os and ws, and arch of x86_64, all of which seem like they should be satisfied by my system. I have included details below, and will update with details that anyone requests.
Background and Problem Details
I'm working on an Eclipse plugin project that hasn't been exported in a long time. It was upgraded from Java 7 to 8, and from Juno to Mars, since the last release. Last week, I went to make a new release, by using the 'Eclipse Product export wizard' in the .product file. Previous releases were fine. Launching the project from within Eclipse works fine (using the product file context menu Run As->Eclipse application to create the Launch configuration). Using the Validate Plug-ins functionality, seen in both the .product and launch config, shows no problems.
The log shows the following:
!SESSION 2016-08-05 09:50:28.847 -----------------------------------------------
eclipse.buildId=unknown
java.version=1.8.0_101
java.vendor=Oracle Corporation
BootLoader constants: OS=${target.os}, ARCH=${target.arch}, WS=${target.ws}, NL=en_US
Framework arguments: -enableassertions
Command-line arguments: -os ${target.os} -ws ${target.ws} -arch ${target.arch} -clean -consoleLog -enableassertions -console
!ENTRY org.eclipse.osgi 4 0 2016-08-05 09:50:30.975
!MESSAGE An error occurred while automatically activating bundle org.eclipse.ui.workbench (96).
!STACK 0
org.osgi.framework.BundleException: Error starting module.
at org.eclipse.osgi.container.Module.doStart(Module.java:580)
...
Caused by: java.lang.NoClassDefFoundError: org/eclipse/swt/SWTError
at java.lang.Class.getDeclaredConstructors0(Native Method)
at java.lang.Class.privateGetDeclaredConstructors(Unknown Source)
at java.lang.Class.getConstructor0(Unknown Source)
at java.lang.Class.newInstance(Unknown Source)
at org.eclipse.osgi.internal.framework.BundleContextImpl.loadBundleActivator(BundleContextImpl.java:755)
at org.eclipse.osgi.internal.framework.BundleContextImpl.start(BundleContextImpl.java:706)
at org.eclipse.osgi.internal.framework.EquinoxBundle.startWorker0(EquinoxBundle.java:941)
at org.eclipse.osgi.internal.framework.EquinoxBundle$EquinoxModule.startWorker(EquinoxBundle.java:318)
at org.eclipse.osgi.container.Module.doStart(Module.java:571)
... 42 more
Caused by: java.lang.ClassNotFoundException: org.eclipse.swt.SWTError cannot be found by org.eclipse.ui.workbench_3.107.0.v20150825-2206
at org.eclipse.osgi.internal.loader.BundleLoader.findClassInternal(BundleLoader.java:439)
at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:352)
at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:344)
at org.eclipse.osgi.internal.loader.ModuleClassLoader.loadClass(ModuleClassLoader.java:160)
at java.lang.ClassLoader.loadClass(Unknown Source)
... 51 more
Root exception:
java.lang.NoClassDefFoundError: org/eclipse/swt/SWTError
...
!ENTRY org.eclipse.osgi 4 0 2016-08-05 09:50:30.988
!MESSAGE An error occurred while automatically activating bundle ca.uvic.chisel.atlantis (2).
!STACK 0
org.osgi.framework.BundleException: Error loading bundle activator.
at org.eclipse.osgi.internal.framework.BundleContextImpl.start(BundleContextImpl.java:711)
etc etc...
I have access to the osgi console, and gotten some more information:
osgi> ss org.eclipse.swt
"Framework is launched."
id State Bundle
82 RESOLVED org.eclipse.swt_3.104.1.v20150825-0743
113 INSTALLED org.eclipse.swt.win32.win32.x86_64_3.104.1.v20150825-0743
osgi> diag 113
org.eclipse.swt.win32.win32.x86_64 [113]
Unresolved requirement: Require-Capability: eclipse.platform; filter:="(& (osg
i.ws=win32) (osgi.os=win32) (osgi.arch=x86_64))"
```
Some more details on SWT on my system...the exported application has "/plugins/org.eclipse.swt.win32.win32.x86_64_3.104.1.v20150825-0743.jar", which is the same version specified by the org.eclipse.swt.win32.win32.x86_64 entry in the .product file's "Plug-ins and Fragments" config. (There is also org.eclipse.swt_3.104.1.v20150825-0743.jar and matching org.eclipse.swt). The bundle fragment requirements are as noted in the osgi console results, namely "(& (osgi.ws=win32) (osgi.os=win32) (osgi.arch=x86_64))".
In the previous (functioning) release from my archives, I see it has org.eclipse.swt.win32.win32.x86_64_3.100.1.v4234e.jar. I do not know if the bundle fragment requirements were the same or different back then. I do not have access to the osgi console in this release, because I did not include the necessary libraries for it back then.
Looking at other bundles, I saw some that are not RESOLVED status either.
Development Context
I am developing, exporting, and running the project on Windows 7. My JRE System Library for dev is jre1.8.0_101-b13. This is the same version (same file path) as the JRE installed for running Java applications.
C:\Atlantis Export\Atlantis 0.3.0 TEST 3>java -XshowSettings:properties -version
Property settings:
awt.toolkit = sun.awt.windows.WToolkit
file.encoding = Cp1252
file.encoding.pkg = sun.io
file.separator = \
java.awt.graphicsenv = sun.awt.Win32GraphicsEnvironment
java.awt.printerjob = sun.awt.windows.WPrinterJob
java.class.path = .
java.class.version = 52.0
java.endorsed.dirs = C:\Program Files\Java\jre1.8.0_101\lib\endorsed
java.ext.dirs = C:\Program Files\Java\jre1.8.0_101\lib\ext
C:\Windows\Sun\Java\lib\ext
java.home = C:\Program Files\Java\jre1.8.0_101
java.io.tmpdir = C:\Users\eric\AppData\Local\Temp\
java.library.path = C:\ProgramData\Oracle\Java\javapath
C:\Windows\Sun\Java\bin
C:\Windows\system32
C:\Windows
C:\ProgramData\Oracle\Java\javapath
C:\Windows\system32
C:\Windows
C:\Windows\System32\Wbem
C:\Windows\System32\WindowsPowerShell\v1.0\
C:\Program Files (x86)\pgmodeler
C:\WinPython-64bit-3.4.3.5\python-3.4.3.amd64
%USERPROFILE%\.dnx\bin
C:\Program Files\Microsoft DNX\Dnvm\
C:\Program Files\nodejs\
C:\Program Files (x86)\Skype\Phone\
C:\Windows\System32\WindowsPowerShell\v1.0\
C:\Program Files\010 Editor
C:\Users\eric\AppData\Roaming\npm
.
java.runtime.name = Java(TM) SE Runtime Environment
java.runtime.version = 1.8.0_101-b13
java.specification.name = Java Platform API Specification
java.specification.vendor = Oracle Corporation
java.specification.version = 1.8
java.vendor = Oracle Corporation
java.vendor.url = http://java.oracle.com/
java.vendor.url.bug = http://bugreport.sun.com/bugreport/
java.version = 1.8.0_101
java.vm.info = mixed mode
java.vm.name = Java HotSpot(TM) 64-Bit Server VM
java.vm.specification.name = Java Virtual Machine Specification
java.vm.specification.vendor = Oracle Corporation
java.vm.specification.version = 1.8
java.vm.vendor = Oracle Corporation
java.vm.version = 25.101-b13
line.separator = \r \n
os.arch = amd64
os.name = Windows 7
os.version = 6.1
path.separator = ;
sun.arch.data.model = 64
sun.boot.class.path = C:\Program Files\Java\jre1.8.0_101\lib\resources.jar
C:\Program Files\Java\jre1.8.0_101\lib\rt.jar
C:\Program Files\Java\jre1.8.0_101\lib\sunrsasign.jar
C:\Program Files\Java\jre1.8.0_101\lib\jsse.jar
C:\Program Files\Java\jre1.8.0_101\lib\jce.jar
C:\Program Files\Java\jre1.8.0_101\lib\charsets.jar
C:\Program Files\Java\jre1.8.0_101\lib\jfr.jar
C:\Program Files\Java\jre1.8.0_101\classes
sun.boot.library.path = C:\Program Files\Java\jre1.8.0_101\bin
sun.cpu.endian = little
sun.cpu.isalist = amd64
sun.desktop = windows
sun.io.unicode.encoding = UnicodeLittle
sun.java.launcher = SUN_STANDARD
sun.jnu.encoding = Cp1252
sun.management.compiler = HotSpot 64-Bit Tiered Compilers
sun.os.patch.level = Service Pack 1
sun.stderr.encoding = cp437
sun.stdout.encoding = cp437
user.country = US
user.dir = C:\Atlantis Export\Atlantis 0.3.0 TEST 3
user.home = C:\Users\eric
user.language = en
user.name = eric
user.script =
user.timezone =
user.variant =
java version "1.8.0_101"
Java(TM) SE Runtime Environment (build 1.8.0_101-b13)
Java HotSpot(TM) 64-Bit Server VM (build 25.101-b13, mixed mode)
I have tried upgrading again from Mars, to Neon. That didn't resolve anything. Downgrading to Juno to fix something like this smells like the wrong solution.

Answer 1

So...while preparing my answer, I found the solution. I know that if I had someone to bounce this off of before, it might have occurred to me then.
I noticed that the ${target.ws} and ${target.os} occur in the launch config. I am not sure how these were added; perhaps the product file generated these arguments, perhaps I added them when trying to fix another bug many moons ago. In any case, I was googling to see how to inspect these values, and decided to simply remove them and test launch and export without them. both worked fine. I don't need them there, I am not sure if they were even containing values.
To reiterate, my solution was to remove the "-os ${target.os} -ws ${target.ws} -arch ${target.arch}" arguments in the .product file (as well as the launch config derived from it).
I may have added them on the advice of somewhere like this (but I don't know why): Eclipse Validation error - Platform filter did not match:(&(osgi.ws=win32)(osgi.os=win32)(osgi.arch=x86)) . Looking at blame, I see that the arguments were added when I first changed the project from using manually defined launch configurations, to using .product based launch configuration; there were inconsistencies and machine dependent strings when the launch was manually defined. I do not know if they were automatically added, or if I thought I needed them.