Building b2 on Cygwin64 fails about b2

[grafikrobot]

This change got merged to the Boost mirror repo already. I.e. I merged the current b2 release, 4.6.1 to Boost. Hence it will show up in the next Boost release.

[Lastique]

It seems, the problem is caused by that build.sh does not define any platform macros, which makes most of the standard library functions unavailable. Adding -D_GNU_SOURCE to compiler arguments fixes the compilation.

[grafikrobot]

Fixed in 2fd5be1 .. Thanks for the report and solution!

[hjmallon]

@grafikrobot : It's not clear to me how the b2 split from boost works? Will this change appear in a boost point release?

[holly564]

Make sure you completed the following tasks
I searched the discussions
I searched the closed and open issues
I read the contribution guidelines

Environment and version details
OS: Windows 10, Cygwin64
Compiler+: GCC 11.1.0
Shell: GNU bash, version 4.4.12(3)-release (x86_64-unknown-cygwin)
B2 Version: b2/4.5.0:171939b47f0d17f8c5eb15e8a8251c598d99fe35 - Build

I updated the toolset in build.sh by adding -D_GNU_SOURCE to compiler arguments like done in the latest version of build.sh

But when I ran build.sh after this it doesn't compile anymore.
The build logs is as follow:
FailedB2BuildCygwin64.txt

[Lastique]

@holly564 Your log shows that you're trying to build with MSVC, which is not installed:

###
### Using 'msvc' toolset.
###

C:\Users\MyComputer\.conan\data\b2\4.5.0\_\_\build\171939b47f0d17f8c5eb15e8a8251c598d99fe35\source\src\engine>"cl" /nologo /MP /MT /TP
/Feb2 /wd4996 /O2 /GL /EHsc   -DNDEBUG  builtins.cpp class.cpp command.cpp compile.cpp constants.cpp cwd.cpp debug.cpp debugger.cpp
 execcmd.cpp execnt.cpp filent.cpp filesys.cpp frames.cpp function.cpp glob.cpp hash.cpp hcache.cpp hdrmacro.cpp headers.cpp jam.cp
p jamgram.cpp lists.cpp make.cpp make1.cpp md5.cpp mem.cpp modules.cpp native.cpp object.cpp option.cpp output.cpp parse.cpp pathnt
.cpp pathsys.cpp regexp.cpp rules.cpp scan.cpp search.cpp jam_strings.cpp startup.cpp subst.cpp sysinfo.cpp timestamp.cpp variable.
cpp w32_getreg.cpp modules/order.cpp modules/path.cpp modules/property-set.cpp modules/regex.cpp modules/sequence.cpp modules/set.c
pp /link kernel32.lib advapi32.lib user32.lib
'"cl"' is not recognized as an internal or external command,
operable program or batch file.

I suspect, you're invoking build.bat or bootstrap.bat instead of the .sh equivalents.

This is unrelated to this bug report.