Compile a SpreadsheetGear.dll file named SpreadsheetGear library with an error

[ezraShenglei]

Steps to Reproduce

1. Compile a SpreadsheetGear.dll file named SpreadsheetGear library with an error

Expected Behavior

Expect to compile this SpreadsheetGear's .net library into a .framework file for use in xcode.

Actual Behavior

Using the objcgen command to directly compile this dll file and using nuget in a Xamarin.iOS Class Library project to reference this SpreadsheetGear library for related operations and then compiling this Class Library project dll file using objcgen will report errors.

Environment

my embeddinator-4000
/Users/wushenglei/.nuget/packages/embeddinator-4000/0.4.0/tools/objcgen
1.
objcgen /Users/wushenglei/.nuget/packages/spreadsheetgear/8.3.25/lib/netstandard1.3/SpreadsheetGear.dll --target=framework --platform=iOS --outdir=output -c --debug

2.objcgen /Users/wushenglei/Projects/hello-from-csharp/hello-from-csharp/bin/Debug/hello_from_csharp.dll --target=framework --platform=iOS --outdir=output -c --debug

Build Logs

https://gist.github.com/chamons/1d0becbbab9a9dde583c2af062cf48a9

[chamons]

I've updated the issue to gist the build log (due to length).

The error in question is rather clear:

error EM0009: The feature `Converting type System.Text.StringBuilder to mono code` is not currently supported by the tool