appveyor and vs2015 deprecation

[beckermr]

To Do

• update to vs2017 (ENH move to vs2017 conda-forge-pinning-feedstock#501)
• bump default in appveyor to vs2017 (ENH bump the appveyor image to vs2017 conda-smithy#1278)
• update the vc feedstock (ENH vs2017 vc-feedstock#11)
• figure out if we need to exempt any feedstocks (ENH appveyor is ok list feedstock-outputs#2)
• need to turn off all appveyor as many feedstocks as possible to prevent new appveyor usage (ENH migrator to cleanup appveyor feedstocks admin-migrations#18, DO NOT MERGE do the branches admin-migrations#21)
• need to remove appveyor from the docs and make an announcement item (DOC appveyor notice #1010)

Feedstock Census

See notes here: https://hackmd.io/@beckermr/rJPw0tnDL/edit

[isuruf]

From the announcements page

We are formally deprecating vs2015 in two weeks on 2020-04-07 and will move to vs2017. This change will enable us to support the usage of msbuild on Azure for the win platform and will provide additional support for C++. Most packages built with vs2015 can be linked with vs2017 toolchain (but not vice-versa). An exception is static libraries compiled with whole program optimization (/GL flag) which may be incompatible with the vs2017 toolchain. These static libraries will need to be rebuilt using vs2017.

[isuruf]

@xhochy, we added /GL by default to CFLAGS env variable in vs2015_win-64 package. So some static libraries might have been created with /GL inadvertently.

[beckermr]

I'm seeing this conda-build warning a lot:

WARNING (lz4-c,Library\bin\liblz4.dll): Needed DSO C:\Windows\System32\VCRUNTIME140.dll not found in any CDT/compiler package, nor the whitelist?!

any ideas anyone?

cc @conda-forge/core @isuruf

[beckermr]

Besides the warning above, the new compiler appears to be working. It has built lz4-c, mpfr, mpc, m4ri and libdb.

[isuruf]

any ideas anyone?

That's a conda-build issue. conda-build checking is case sensitive, when it shouldn't be.

[beckermr]

I think overall the new compiler is good to go.

[beckermr]

All of the work here is done! Closing!