Bisect to figure out why CI is timing out on nightly

[DilumAluthge]

No description provided.

[DilumAluthge]

Here is the result of bisecting:

6c4f2165619449182693061e07654b399428e0cf is the first bad commit
commit 6c4f2165619449182693061e07654b399428e0cf
Author: Jameson Nash <vtjnash@gmail.com>
Date:   Thu Jul 29 12:05:08 2021 -0400

    add stream shutdown and support half-duplex operation (#40783)

    Fixes one of the issues mentioned in #24526

 NEWS.md                                    |   1 +
 base/coreio.jl                             |   1 +
 base/exports.jl                            |   1 +
 base/io.jl                                 | 124 +++++++++++++++------------
 base/iobuffer.jl                           |   6 ++
 base/libuv.jl                              |   1 +
 base/process.jl                            |   1 +
 base/stream.jl                             | 132 +++++++++++++++++++++--------
 doc/src/base/io-network.md                 |   1 +
 stdlib/Distributed/src/process_messages.jl |   4 +-
 stdlib/Sockets/src/Sockets.jl              |  15 ++--
 stdlib/Sockets/test/runtests.jl            |  35 ++++++--
 test/iobuffer.jl                           |  21 +++--
 test/spawn.jl                              |   8 ++
 14 files changed, 240 insertions(+), 111 deletions(-)

The first bad commit is JuliaLang/julia@6c4f216, which corresponds to pull request JuliaLang/julia#40783.

Here's the bisect log:

$ git bisect log
git bisect start
# bad: [cdd2f30d445756377ed154450384461ebc3f3a9c] inference: `prioritize force_constant_prop` over `const_prop_entry_heuristic` (#41882)
git bisect bad cdd2f30d445756377ed154450384461ebc3f3a9c
# good: [1fd46e6251b7e8fd60559ed513144efdbb69cb7c] Set VERSION to 1.8.0-DEV, move 1.7 NEWS to HISTORY (#41122)
git bisect good 1fd46e6251b7e8fd60559ed513144efdbb69cb7c
# good: [361b3a48e2ce05a05f7e3c01903d18bf114432e3] Merge pull request #41567 from JuliaLang/jq/generic_bitstring
git bisect good 361b3a48e2ce05a05f7e3c01903d18bf114432e3
# bad: [705f489f3fb70cbe891ac6b898a71f4abc3bb11e] 🤖 Bump the Pkg stdlib from 39cc95a6 to 5434d05f (#41766)
git bisect bad 705f489f3fb70cbe891ac6b898a71f4abc3bb11e
# good: [0aa7a8382093b40ebdbcf351e76de455ae3a06e9] update common_symbols (#41490)
git bisect good 0aa7a8382093b40ebdbcf351e76de455ae3a06e9
# good: [5f4c719d67a37cb9e227f99dc44b17e9b0c5f971] Merge pull request #41644 from JuliaLang/vc/emit_signal_fence
git bisect good 5f4c719d67a37cb9e227f99dc44b17e9b0c5f971
# bad: [795935fd3a2d97b2f948cfb82a18da48743b622d] more type-stable type-inference (#41697)
git bisect bad 795935fd3a2d97b2f948cfb82a18da48743b622d
# good: [d066a8eab3e7065d3203614f4bfbd1857a5694d2] doc: explain how to enable debug for multiple modules (#41719)
git bisect good d066a8eab3e7065d3203614f4bfbd1857a5694d2
# good: [fa30e64987dc1740773f9c9cc60a3afc85959cb5] Merge pull request #41685 from JuliaLang/vc/gc_probes
git bisect good fa30e64987dc1740773f9c9cc60a3afc85959cb5
# bad: [66f9b55e3bf40f03e49cd95008ba1d7c709ca127] Revert "Merge pull request #38405 from JuliaLang/vc/distributed_ts" (#41722)
git bisect bad 66f9b55e3bf40f03e49cd95008ba1d7c709ca127
# bad: [6c4f2165619449182693061e07654b399428e0cf] add stream shutdown and support half-duplex operation (#40783)
git bisect bad 6c4f2165619449182693061e07654b399428e0cf
# first bad commit: [6c4f2165619449182693061e07654b399428e0cf] add stream shutdown and support half-duplex operation (#40783)