Steps to reproduce:

Build firefox-104.0 on FreeBSD 12.x 32-bit (i386):

make -C /usr/ports/www/firefox build

Actual results:

Compiler error (redefinition 'double' vs 'long double'):

/usr/local/bin/clang++13 -std=gnu++17 -o e_acos.o -c  -I/wrkdirs/usr/ports/www/firefox/work/.build/dist/stl_wrappers -I/wrkdirs/usr/ports/www/firefox/work/.build/dist/system_wrappers -include /wrkdirs/usr/ports/www/firefox/work/firefox-107.0/config/gcc_hidden.h -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 -fstack-protector-strong -fstack-clash-protection -DNDEBUG=1 -DTRIMMED=1 -DEXPORT_JS_API -DMOZ_HAS_MOZGLUE -I/wrkdirs/usr/ports/www/firefox/work/firefox-107.0/modules/fdlibm/src -I/wrkdirs/usr/ports/www/firefox/work/.build/modules/fdlibm/src -I/wrkdirs/usr/ports/www/firefox/work/.build/dist/include -I/usr/local/include/nspr -I/usr/local/include -I/usr/local/include/nss -I/usr/local/include/nspr -I/wrkdirs/usr/ports/www/firefox/work/.build/dist/include/nss -I/usr/local/include -I/usr/local/include/libpng16 -I/usr/local/include/pixman-1 -I/usr/local/include -DMOZILLA_CLIENT -include /wrkdirs/usr/ports/www/firefox/work/.build/mozilla-config.h -Qunused-arguments -DLIBICONV_PLUG -isystem /usr/local/include -Qunused-arguments -Wall -Wbitfield-enum-conversion -Wdeprecated-this-capture -Wempty-body -Wformat-type-confusion -Wignored-qualifiers -Wpointer-arith -Wshadow-field-in-constructor-modified -Wsign-compare -Wtype-limits -Wno-error=tautological-type-limit-compare -Wunreachable-code -Wunreachable-code-return -Wunused-but-set-parameter -Wno-invalid-offsetof -Wclass-varargs -Wempty-init-stmt -Wfloat-overflow-conversion -Wfloat-zero-conversion -Wloop-analysis -Wno-range-loop-analysis -Wc++2a-compat -Wenum-compare-conditional -Wno-ambiguous-reversed-operator -Wno-error=deprecated -Wno-error=deprecated-anon-enum-enum-conversion -Wno-error=deprecated-enum-enum-conversion -Wno-error=deprecated-enum-float-conversion -Wno-error=deprecated-this-capture -Wno-error=deprecated-volatile -Wcomma -Wimplicit-fallthrough -Wstring-conversion -Wno-inline-new-delete -Wno-error=deprecated-declarations -Wno-error=array-bounds -Wno-error=free-nonheap-object -Wno-error=atomic-alignment -Wformat -Wformat-security -Wno-psabi -Wthread-safety -Wno-unknown-warning-option -fno-sized-deallocation -fno-aligned-new -O2 -pipe -O3 -DLIBICONV_PLUG -fstack-protector-strong -isystem /usr/local/include -fno-strict-aliasing -DLIBICONV_PLUG -isystem /usr/local/include -fno-exceptions -fPIC -fno-rtti -ffunction-sections -fdata-sections -fno-exceptions -fno-math-errno -pipe -O2 -O3 -fno-omit-frame-pointer -funwind-tables -Wno-parentheses -Wno-sign-compare -Wno-dangling-else -fno-strict-aliasing -ffp-contract=off  -MD -MP -MF .deps/e_acos.o.pp   /wrkdirs/usr/ports/www/firefox/work/firefox-107.0/modules/fdlibm/src/e_acos.cpp
modules/fdlibm/src/e_acosh.o
In file included from /wrkdirs/usr/ports/www/firefox/work/firefox-107.0/modules/fdlibm/src/e_acos.cpp:44:
/wrkdirs/usr/ports/www/firefox/work/firefox-107.0/modules/fdlibm/src/math_private.h:33:21: error: typedef redefinition with different types ('double' vs 'long double')
typedef double      __double_t;
                    ^
/usr/include/x86/_types.h:87:21: note: previous definition is here
typedef long double     __double_t;
                        ^
In file included from /wrkdirs/usr/ports/www/firefox/work/firefox-107.0/modules/fdlibm/src/e_acos.cpp:44:
/wrkdirs/usr/ports/www/firefox/work/firefox-107.0/modules/fdlibm/src/math_private.h:35:21: error: typedef redefinition with different types ('float' vs 'long double')
typedef float       __float_t;
                    ^
/usr/include/x86/_types.h:88:21: note: previous definition is here
typedef long double     __float_t;
                        ^
2 errors generated.

This was first noticed in Firefox 105.

See also https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=266470

The Bugbug bot thinks this bug should belong to the 'Firefox Build System::General' component, and is moving the bug to that component. Please correct in case you think the bot is wrong.

Duplicate of bug 1729459.