The new Mono 6.12 is unable to run

I just noticed that after the update, none of my Docker containers are building. I get this error:

Step 5/7 : RUN cert-sync /etc/ssl/certs/ca-certificates.crt
 ---> Running in 8ad6df2b4427
Error: System.TypeInitializationException: The type initializer for 'Sys' threw an exception. ---> System.DllNotFoundException: /usr/lib/../lib/libmono-native.so assembly:<unknown assembly> type:<unknown type> member:(null)
  at (wrapper managed-to-native) Interop+Sys.LChflagsCanSetHiddenFlag()
  at Interop+Sys..cctor () [0x00000] in <b061b40c53d642f4828de65bcd420f39>:0 
   --- End of inner exception stack trace ---
  at System.IO.FileSystem.FileExists (System.ReadOnlySpan`1[T] fullPath, System.Int32 fileType, Interop+ErrorInfo& errorInfo) [0x00007] in <b061b40c53d642f4828de65bcd420f39>:0 
  at System.IO.FileSystem.FileExists (System.ReadOnlySpan`1[T] fullPath) [0x00006] in <b061b40c53d642f4828de65bcd420f39>:0 
  at System.IO.File.Exists (System.String path) [0x00043] in <b061b40c53d642f4828de65bcd420f39>:0 
  at Mono.Tools.CertSync.ParseOptions (System.String[] args) [0x0007c] in <f333807f951849719474ff0c315730f8>:0 
  at Mono.Tools.CertSync.Main (System.String[] args) [0x00000] in <f333807f951849719474ff0c315730f8>:0 
The command '/bin/sh -c cert-sync /etc/ssl/certs/ca-certificates.crt' returned a non-zero code: 1

My full Docker file is:

FROM amd64/alpine:3.9

RUN apk add --no-cache bash curl ca-certificates python git build-base ninja fontconfig-dev
RUN apk add --no-cache samurai --repository http://dl-cdn.alpinelinux.org/alpine/edge/main
RUN apk add --no-cache mono clang gn --repository http://dl-cdn.alpinelinux.org/alpine/edge/testing
RUN cert-sync /etc/ssl/certs/ca-certificates.crt

ENV GN_EXE=gn NINJA_EXE=ninja

WORKDIR /work