0.5.0 --- repin the C library, whose backends fixed a bounded transfer

openkal-musl 0.9.0 answers `truncate(2)`, repins openkal-linux 0.7.1 and
openkal-macos 0.6.1, and makes a build able to state which version of the C
library it holds.

WHAT A PROGRAM ABOVE THIS PACKAGE GETS. Two things that did not work now do,
and neither is a C++ problem --- both are `std::filesystem` reaching a system
call.

`std::filesystem::copy_file` reported `Resource temporarily unavailable` for two
ordinary files. libc++ opens a copy's source with `O_RDONLY | O_NONBLOCK |
O_BINARY`, which on a kernel is meaningless for a regular file and is ignored;
openkal-musl routes an `O_NONBLOCK` descriptor through the bounded-transfer path
and expresses `copy_file_range` as a read/write loop, so every byte of a file
copy went through it --- and the backends' `kal_timeout_read` decoded a borrowed
`kal_stream` handle with the decoder for an OWNED one, waiting upon the
descriptor below the one it then transferred upon. `EAGAIN` is not in libc++'s
fallback list, so it fell back neither to `sendfile` nor to a stream copy and
the error reached the caller verbatim.

`std::filesystem::resize_file` worked for no path at all, because libc++
expresses it as the name-shaped `truncate` and only the descriptor-shaped one
was answered.

Both reported in mcpplibs/openkal-linux#13.

AND A CONSUMER CAN NOW SAY WHAT IT BUILT. `OPENKAL_MUSL_TRACE=enosys` names the
C library's version before the program runs, whether or not anything is missing,
and `uname`'s release field carries it too. Two rounds of that issue were
answered against the wrong version because neither existed.

Also here: the two fetches of the installer retry transport failures. `--retry`
covers a transient HTTP status and a timeout and does not cover
`curl: (35) Recv failure: Connection reset by peer`, which is what a row of a
sibling repository's matrix met today, thirteen seconds in, with nothing wrong
in it.

Author: Sunrisepeak

.github/workflows/ci.yml

@@ -46,7 +46,13 @@ jobs:
 
       - name: Install xlings and mcpp
         run: |
-          curl -fsSL https://raw.githubusercontent.com/openxlings/xlings/main/tools/other/quick_install.sh \
+          # --retry-all-errors and not --retry alone: the first covers a
+          # transient HTTP status and a timeout, and what this step meets is a
+          # failure of the transport. Observed in this ecosystem as
+          # `curl: (35) Recv failure: Connection reset by peer', thirteen
+          # seconds into a job, before anything was built.
+          curl -fsSL --retry 3 --retry-all-errors --retry-delay 2 \
+            https://raw.githubusercontent.com/openxlings/xlings/main/tools/other/quick_install.sh \
             | bash -s "$XLINGS_VERSION"
           echo "$HOME/.xlings/subos/current/bin" >> "$GITHUB_PATH"
 
@@ -464,7 +470,13 @@ jobs:
       - name: Install xlings (Unix)
         if: runner.os != 'Windows'
         run: |
-          curl -fsSL https://raw.githubusercontent.com/openxlings/xlings/main/tools/other/quick_install.sh \
+          # --retry-all-errors and not --retry alone: the first covers a
+          # transient HTTP status and a timeout, and what this step meets is a
+          # failure of the transport. Observed in this ecosystem as
+          # `curl: (35) Recv failure: Connection reset by peer', thirteen
+          # seconds into a job, before anything was built.
+          curl -fsSL --retry 3 --retry-all-errors --retry-delay 2 \
+            https://raw.githubusercontent.com/openxlings/xlings/main/tools/other/quick_install.sh \
             | bash -s "$XLINGS_VERSION"
           echo "$HOME/.xlings/subos/current/bin" >> "$GITHUB_PATH"
 

README.md

@@ -6,7 +6,7 @@ C library.
 
 ```toml
 [dependencies]
-openkal-llvm-runtime = "0.4.0"
+openkal-llvm-runtime = "0.5.0"
 ```
 
 A C++ standard library is not portable in the way a program is. It is

mcpp.toml

@@ -1,7 +1,7 @@
 [package]
 namespace   = "mcpplibs"
 name        = "openkal-llvm-runtime"
-version     = "0.4.0"
+version     = "0.5.0"
 description = "LLVM's C++ runtime libraries — libc++, libc++abi and libunwind — configured for openkal-musl rather than for a host C library."
 license     = "Apache-2.0"
 authors     = ["mcpplibs"]
@@ -208,7 +208,7 @@ sources = [
 cflags = ["-DDISABLE_AARCH64_FMV=1"]
 
 [dependencies]
-openkal-musl = "0.7.0"
+openkal-musl = "0.9.0"
 
 [build]
 cxx_standard = "c++23"