use standard triplet

Dockerfile

@@ -74,6 +74,7 @@ ARG PLATFORM=x64
 # based on https://github.com/PointCloudLibrary/pcl/blob/c1757b554db314699620612ba2e27c0c12141740/.dev/docker/windows/Dockerfile
 #COPY $PLATFORM'-windows-rel.cmake' 'c:\vcpkg\triplets\'$PLATFORM'-windows-rel.cmake'
 
+#ENV VCPKG_DEFAULT_TRIPLET "x64-windows-release"
 #SHELL ["powershell", "-Command", "$ErrorActionPreference = 'Stop'; $ProgressPreference = 'SilentlyContinue';"]
 RUN where vcpkg
 RUN vcpkg integrate install
@@ -85,14 +86,12 @@ RUN vcpkg install `
     suitesparse-spqr `
     pkgconf `
     yasm-tool:x86-windows `
-    --triplet $Env:PLATFORM-windows-release --host-triplet $Env:PLATFORM-windows-release --clean-after-build
+    --clean-after-build
 
     #metis
     #coin-or-ipopt
 
-#RUN vcpkg install `
-#    cgal `
-# --triplet $Env:PLATFORM-windows-rel --host-triplet $Env:PLATFORM-windows-rel --clean-after-build
+RUN vcpkg install ipopt --clean-after-build
 
 # This is for later use in containers, cache does not exist here.
 # Therefore, only set this after we're done with vcpkg:

x64-windows-rel.cmake

-set(VCPKG_TARGET_ARCHITECTURE x64)
-set(VCPKG_CRT_LINKAGE dynamic)
-set(VCPKG_LIBRARY_LINKAGE dynamic)
-set(VCPKG_BUILD_TYPE release)