Add Windows installation via conda-forge

[mabelzhang]

Partially addresses gazebosim/docs#117

This replaces the old Windows installation instructions from Nov 2017, which installed dependencies by zip files and used nmake with VS 2013 on Windows 7 and 8. We have now decided to go with conda-forge, tested with VS 2019 on Windows 10.

The current instructions built and installed, but I'm unsure about two things, which may be optional.

1. CMake warning about IFADDRS

I got a CMake warning about missing IFADDRS:

-- BUILD WARNINGS
--      Missing: IFADDRS
-- END BUILD WARNINGS

I tried installing ifaddr, but that didn't fix the warning after removing the build directory and rerunning cmake:

conda install -c conda-forge ifaddr

Seeing that ifaddr is for network interfaces, and this is transport, I don’t know if that warning can be ignored.
What does it affect specifically, do we need to find it?

2. Errors building example/

The old instructions built the examples and ran responser and requester.
I wanted to keep that, but I wasn’t able to build the examples. I can run up to this:

cd ign-transport\example
mkdir build
cd build
# I used a custom -DCMAKE_INSTALL_PREFIX and had to specify the path to ignition-transport9-config.cmake
cmake .. -DCMAKE_PREFIX_PATH=Z:\sim\ign_ws\install\ignition-transport9\lib\cmake\ignition-transport9

Then when I ran

cmake --build .

I got a lot of warnings and a few errors.

Microsoft (R) Build Engine version 16.8.2+25e4d540b for .NET Framework
Copyright (C) Microsoft Corporation. All rights reserved.

  Checking Build System
  Building Custom Rule Z:/sim/ign_ws/src/ign-transport/example/CMakeLists.txt
  publisher.cc
  publisher.vcxproj -> Z:\sim\ign_ws\src\ign-transport\example\build\Debug\publisher.exe
  Building Custom Rule Z:/sim/ign_ws/src/ign-transport/example/CMakeLists.txt
  publisher_c.cc
Z:\sim\ign_ws\src\ign-transport\example\publisher_c.cc(18,10): fatal error C1083: Cannot open in
clude file: 'unistd.h': No such file or directory [Z:\sim\ign_ws\src\ign-transport\example\build
\publisher_c.vcxproj]
  Building Custom Rule Z:/sim/ign_ws/src/ign-transport/example/CMakeLists.txt
  publisher_c_fast.cc
Z:\sim\ign_ws\src\ign-transport\example\publisher_c_fast.cc(18,10): fatal error C1083: Cannot op
en include file: 'unistd.h': No such file or directory [Z:\sim\ign_ws\src\ign-transport\example\
build\publisher_c_fast.vcxproj]
  Running cpp protocol buffer compiler on stringmsg.proto
  Building Custom Rule Z:/sim/ign_ws/src/ign-transport/example/msgs/CMakeLists.txt
  Building Custom Rule Z:/sim/ign_ws/src/ign-transport/example/CMakeLists.txt
  publisher_custom_msg.cc
C:\Users\mabel\miniconda3\envs\ign-ws\Library\include\google/protobuf/stubs/logging.h(102,23): w
arning C4251: 'google::protobuf::internal::LogMessage::message_': class 'std::basic_string<char,
std::char_traits<char>,std::allocator<char>>' needs to have dll-interface to be used by clients
of class 'google::protobuf::internal::LogMessage' [Z:\sim\ign_ws\src\ign-transport\example\build
\publisher_custom_msg.vcxproj]
C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Tools\MSVC\14.28.29333\include\
xstring(4648): message : see declaration of 'std::basic_string<char,std::char_traits<char>,std::
allocator<char>>' [Z:\sim\ign_ws\src\ign-transport\example\build\publisher_custom_msg.vcxproj]
C:\Users\mabel\miniconda3\envs\ign-ws\Library\include\google/protobuf/io/coded_stream.h(1250,64)
: warning C4251: 'google::protobuf::io::CodedOutputStream::default_serialization_deterministic_'
: struct 'std::atomic<bool>' needs to have dll-interface to be used by clients of class 'google:
:protobuf::io::CodedOutputStream' [Z:\sim\ign_ws\src\ign-transport\example\build\publisher_custo
m_msg.vcxproj]
C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Tools\MSVC\14.28.29333\include\
atomic(2759): message : see declaration of 'std::atomic<bool>' [Z:\sim\ign_ws\src\ign-transport\
example\build\publisher_custom_msg.vcxproj]
... # more warnings
msgs\stringmsg.pb.cc : fatal error LNK1107: invalid or corrupt file: cannot read at 0x3028 [Z:\s
im\ign_ws\src\ign-transport\example\build\publisher_custom_msg.vcxproj]
... # more warnings
msgs\stringmsg.pb.cc : fatal error LNK1107: invalid or corrupt file: cannot read at 0x3028 [Z:\s
im\ign_ws\src\ign-transport\example\build\subscriber_custom_msg.vcxproj]
... # more warnings

[codecov]

Codecov Report

Merging #207 (fc1e3b8) into ign-transport9 (72dfeb8) will decrease coverage by 0.00%.
The diff coverage is n/a.

@@                Coverage Diff                 @@
##           ign-transport9     #207      +/-   ##
==================================================
- Coverage           88.98%   88.98%   -0.01%     
==================================================
  Files                  49       47       -2     
  Lines                4668     4484     -184     
==================================================
- Hits                 4154     3990     -164     
+ Misses                514      494      -20     

Impacted Files	Coverage Δ
src/NodeShared.cc	79.06% <0.00%> (-0.49%)	⬇️
src/Node.cc	92.32% <0.00%> (-0.02%)	⬇️
src/NodeSharedPrivate.hh	100.00% <0.00%> (ø)
src/TopicStatistics.cc
include/ignition/transport/TopicStatistics.hh
include/ignition/transport/Discovery.hh	87.86% <0.00%> (+0.13%)	⬆️

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[traversaro]

I got a lot of warnings and a few errors.

I am not sure if the error is related to that, but conda-forge only ships Release libraries, and from the output of the example it seems that you are compiling the examples in Debug mode. Unfortunately, the C++ STL library that ships with MSVC has different ABIs in Release and in Debug, so if you compile the libraries in Release, you need to also compiles the examples in Release or RelWithDebInfo. On Linux/macOS the situation is different because both libstdcxx and libcxx are ABI compatible between Release and Debug builds.

[traversaro]

Then I think that the header https://github.com/ignitionrobotics/ign-transport/blob/ign-transport9/example/publisher_c.cc#L18 is Unix-only and can be probably dropped with no problems.

[JShep1]

A couple feedback comments, but LGTM

[JShep1]

For me, the executables are placed within a Debug folder, should we add --config Release to the above build command?

[JShep1]

I had to run in admin mode to get the install to work, maybe a note here indicating that the user will need to do that too if they wish to install.

[JShep1]

Closing this PR in favor of retargeting to Citadel. #214