ARROW-8164: [C++][Dataset] Provide Dataset::ReplaceSchema()

[bkietz]

No description provided.

[github-actions]

https://issues.apache.org/jira/browse/ARROW-8164

[fsaintjacques]

Can you rebase with master, there's a lot of failing test noise. My approval is pending at least a checkup of the failures :)

[bkietz]

CI failures are s3fs, grpc build failure x2 x3, and RTools flake

[nealrichardson]

It's not clear that the R Windows failure is a flake, it reads similar to https://issues.apache.org/jira/browse/ARROW-8217

[jorisvandenbossche]

There is still a R failure (don't know whether this is related), and windows is failing in cmake (related to googletest)

[nealrichardson]

If I read this diff correctly, the only place that the R package tests should touch new code (i.e. without calling ReplaceSchema, which has a binding added but no test) is here. Is there something suspicious about CheckProjectable (on 32-bit mingw)?

[nealrichardson]

R is passing on master, so we need to figure out why it's failing here.

[nealrichardson]

Reproduced the crash locally. https://github.com/apache/arrow/blob/master/r/tests/testthat/test-json.R#L30 is where it exits. Can't get a backtrace with gdb, even with a debug build.

[nealrichardson]

@bkietz Here's an even shorter repro, reduced from the test that blows up:

library(arrow)
tf <- tempfile()
writeLines('{ "hello": 3.5 }\n', tf, useBytes = TRUE)
read_json_arrow(tf, as_data_frame = FALSE)

[nealrichardson]

I did some more interactive exploration of this in R, and found that the crash happens when calling arrow::json::TableReader's Read() method.

[nealrichardson]

🎉 @bkietz the Rtools build is passing now! But now 6 other things are failing. Should check if they're flakes or if we broke something else in this flailing.

[nealrichardson]

merging 🤞