FreeBSD bus error in boost::locale::conv when charmap is not set

[lambdafu]

System: FreeBSD 11.1-RELEASE (GENERIC)

[~/neopg/build]$ gdb src/neopg 
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This GDB was configured as "amd64-marcel-freebsd"...
(gdb) run 
Starting program: /usr/home/lambdafu/neopg/build/src/neopg 
warning: Lowest section in /usr/local/lib/libicudata.so.59 is .hash at 0000000000000120

Program received signal SIGBUS, Bus error.
0x0000000800f20155 in boost::locale::conv::impl::convert_to<wchar_t> () from /usr/local/lib/libboost_locale.so.1.64.0
(gdb) bt
#0  0x0000000800f20155 in boost::locale::conv::impl::convert_to<wchar_t> () from /usr/local/lib/libboost_locale.so.1.64.0
#1  0x0000000800f1f89d in boost::locale::conv::to_utf<wchar_t> () from /usr/local/lib/libboost_locale.so.1.64.0
#2  0x0000000800f3afb1 in boost::locale::util::simple_converter_impl::simple_converter_impl () from /usr/local/lib/libboost_locale.so.1.64.0
#3  0x0000000800f3ac23 in boost::locale::util::create_simple_codecvt () from /usr/local/lib/libboost_locale.so.1.64.0
#4  0x0000000800f3e7ac in boost::locale::impl_icu::create_codecvt () from /usr/local/lib/libboost_locale.so.1.64.0
#5  0x0000000800f49b1a in boost::locale::impl_icu::icu_localization_backend::install () from /usr/local/lib/libboost_locale.so.1.64.0
#6  0x0000000800f2d7e8 in boost::locale::localization_backend_manager::impl::actual_backend::install () from /usr/local/lib/libboost_locale.so.1.64.0
#7  0x0000000800f29b27 in boost::locale::generator::generate () from /usr/local/lib/libboost_locale.so.1.64.0
#8  0x0000000800f298fd in boost::locale::generator::generate () from /usr/local/lib/libboost_locale.so.1.64.0
#9  0x000000000068b574 in boost::locale::generator::operator() (this=0x7fffffff9608, id=@0x7fffffff95a0) at generator.hpp:202
#10 0x0000000000679f3f in setup_locale () at /usr/home/lambdafu/neopg/src/neopg.cpp:28
#11 0x000000000066eb8e in main (argc=1, argv=0x7fffffffeb18) at /usr/home/lambdafu/neopg/src/neopg.cpp:105
(gdb) 

Locale settings:

$ locale   
LANG=
LC_CTYPE="C"
LC_COLLATE="C"
LC_TIME="C"
LC_NUMERIC="C"
LC_MONETARY="C"
LC_MESSAGES="C"
LC_ALL=

As a work-around, setting the charmap for LC_CTYPE to basically any value works:

$ LC_CTYPE=en_US.UTF-8 src/neopg 
NeoPG implements the OpenPGP standard.
Usage: src/neopg [OPTIONS] [SUBCOMMAND]
[...]

[fkr]

Seems to be same as this problem reported over at freebsd: https://bugs.freebsd.org/bugzilla/show_bug.cgi?format=multiple&id=222125

[lambdafu]

@frk Indeed. This is probably a bug in boost, because it doesn't happen under Linux even if I try to set the locale in the same way.