git-annex/doc/bugs/aws_0.16_breaking_changes.mdwn

### Please describe the problem.
aws-0.16 and 0.15.1 were just released. 0.16 has breaking changes.

### What steps will reproduce the problem?
Try to build git-annex with the S3 flag with aws-0.16.

Note that git-annex builds successfully with 0.15.1, and that 0.15 has its own problems since it constrains xml-conduit to < 1.4, which fails unless blaze-markup is also contrained to < 0.8.0.0. This is resolved by using 0.15.1 since it lifted the contraint on xml-conduit to < 1.5.

### What version of git-annex are you using? On what operating system?
6.20170101 on macOS

### Please provide any additional information below.
The build failure is
[[!format sh """
[323 of 546] Compiling Remote.Glacier   ( Remote/Glacier.hs, dist/dist-sandbox-8fbcd4b9/build/git-annex/git-annex-tmp/Remote/Glacier.o )
[324 of 546] Compiling Remote.Helper.Http ( Remote/Helper/Http.hs, dist/dist-sandbox-8fbcd4b9/build/git-annex/git-annex-tmp/Remote/Helper/Http.o )
[325 of 546] Compiling Remote.S3        ( Remote/S3.hs, dist/dist-sandbox-8fbcd4b9/build/git-annex/git-annex-tmp/Remote/S3.o )

Remote/S3.hs:224:49: error:
    • The constructor ‘S3.UploadPartResponse’ should have 1 argument, but has been given 2
    • In the pattern: S3.UploadPartResponse _ etag
      In a stmt of a 'do' block:
        S3.UploadPartResponse _ etag <- sendS3Handle h req
      In the expression:
        do { let sz = ...;
             let p' = offsetMeterUpdate p (toBytesProcessed pos);
             let numchunks
                   = ceiling
                       (fromIntegral sz / fromIntegral defaultChunkSize :: Double);
             let popper = handlePopper numchunks defaultChunkSize p' fh;
             .... }
cabal: Leaving directory '.'
cabal: Error: some packages failed to install:
git-annex-6.20170101 failed during the building phase. The exception was:
ExitFailure 1
/usr/local/Homebrew/Library/Homebrew/debrew.rb:11:in `raise'
BuildError: Failed executing: cabal install --jobs=8 --max-backjumps=100000 --prefix=/usr/local/Cellar/git-annex/6.20170101_1 --flags=s3\ webapp
"""]]

### Have you had any luck using git-annex before? (Sometimes we get tired of reading bug reports all day and a lil' positive end note does wonders)

Yes!

> [[fixed|done]] thanks --[[Joey]]