The build fails on armhf linux because it is assumed to be android. Also, there are conflicting symbols.

[task 2021-11-02T21:34:38.579Z] 21:34:38     INFO -  /builds/worker/fetches/clang/bin/clang++ --sysroot /builds/worker/fetches/sysroot-arm-linux-gnueabihf -std=gnu++17 --target=arm-linux-gnueabihf -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 -fstack-protector-strong -Qunused-arguments -Qunused-arguments -Wall -Wbitfield-enum-conversion -Wdeprecated-this-capture -Wempty-body -Wformat-type-confusion -Wignored-qualifiers -Wpointer-arith -Wshadow-field-in-constructor-modified -Wshadow-uncaptured-local -Wsign-compare -Wtype-limits -Wno-error=tautological-type-limit-compare -Wunreachable-code -Wunreachable-code-return -Wno-invalid-offsetof -Wclass-varargs -Wempty-init-stmt -Wfloat-overflow-conversion -Wfloat-zero-conversion -Wloop-analysis -Wno-range-loop-analysis -Wc++2a-compat -Wcomma -Wenum-compare-conditional -Wimplicit-fallthrough -Wstring-conversion -Wno-inline-new-delete -Wno-error=deprecated-declarations -Wno-error=array-bounds -Wno-error=backend-plugin -Wno-error=free-nonheap-object -Wno-error=return-std-move -Wno-error=atomic-alignment -Wno-error=deprecated-copy -Wformat -Wformat-security -Wno-gnu-zero-variadic-macro-arguments -Wno-psabi -Wno-unknown-warning-option -fno-sized-deallocation -fno-aligned-new -fcrash-diagnostics-dir=/builds/worker/artifacts -march=armv7a -fno-exceptions -fno-strict-aliasing -funwind-tables -fPIC -fno-rtti -ffunction-sections -fdata-sections -fno-exceptions -fno-math-errno -pthread -pipe -g -O2 -fno-omit-frame-pointer -funwind-tables  -shared -Wl,-z,defs -Wl,--gc-sections -Wl,-h,libxul.so -o libxul.so /builds/worker/workspace/obj-build/toolkit/library/gtest/libxul_so.list   -lpthread -fuse-ld=bfd -Wl,-rpath-link,/builds/worker/fetches/sysroot-arm-linux-gnueabihf/lib/arm-linux-gnueabihf -Wl,-rpath-link,/builds/worker/fetches/sysroot-arm-linux-gnueabihf/usr/lib/arm-linux-gnueabihf -Wl,-z,noexecstack -Wl,-z,text -Wl,-z,relro -Wl,-z,nocopyreloc -Wl,-Bsymbolic-functions -Wl,--build-id=sha1 -fstack-protector-strong -Wl,-rpath-link,/builds/worker/workspace/obj-build/dist/bin -Wl,-rpath-link,/usr/local/lib  ../../../security/nss/lib/crmf/crmf_crmf/libcrmf.a ../../../js/src/build/libjs_static.a /builds/worker/workspace/obj-build/armv7-unknown-linux-gnueabihf/release/libgkrust_gtest.a ../../../security/sandbox/linux/libmozsandbox.so ../../../config/external/nspr/pr/libnspr4.so ../../../config/external/nspr/libc/libplc4.so ../../../config/external/nspr/ds/libplds4.so ../../../config/external/lgpllibs/liblgpllibs.so ../../../security/nss/lib/nss/nss_nss3/libnss3.so ../../../security/nss/lib/util/util_nssutil3/libnssutil3.so ../../../security/nss/lib/smime/smime_smime3/libsmime3.so ../../../config/external/sqlite/libmozsqlite3.so ../../../security/nss/lib/ssl/ssl_ssl3/libssl3.so ../../../widget/gtk/mozgtk/libmozgtk.so ../../../widget/gtk/mozwayland/libmozwayland.so -Wl,--version-script,symverscript  -ldl  -landroid_support -lunwind -lrt -lm -ldl -lX11 -lXcomposite -lXdamage -lXext -lXfixes -lXrandr -lXrender -lXtst -lpthread -lc -L/builds/worker/fetches/sysroot-arm-linux-gnueabihf/usr/lib/arm-linux-gnueabihf -lfreetype -lfontconfig -lgtk-3 -lgdk-3 -lpangocairo-1.0 -lpango-1.0 -latk-1.0 -lcairo-gobject -lcairo -lgdk_pixbuf-2.0 -lgio-2.0 -lgobject-2.0 -lglib-2.0 -ldbus-glib-1 -ldbus-1 -lxcb-shm -lX11-xcb -lxcb -lXcursor -lXi
[task 2021-11-02T21:34:38.579Z] 21:34:38     INFO -  /builds/worker/fetches/binutils/bin/ld.bfd: /builds/worker/workspace/obj-build/toolkit/library/gtest/../../../third_party/libwebrtc/common_audio/common_audio_c_gn/Unified_c_common_audio_c_gn0.o: in function `WebRtcSpl_ComplexBitReverse':
[task 2021-11-02T21:34:38.579Z] 21:34:38     INFO -  /builds/worker/checkouts/gecko/third_party/libwebrtc/common_audio/signal_processing/complex_bit_reverse.c:49: multiple definition of `WebRtcSpl_ComplexBitReverse'; /builds/worker/workspace/obj-build/toolkit/library/gtest/../../../third_party/libwebrtc/common_audio/common_audio_c_arm_asm_gn/complex_bit_reverse_arm.o:/builds/worker/checkouts/gecko/third_party/libwebrtc/common_audio/signal_processing/complex_bit_reverse_arm.S:20: first defined here
[task 2021-11-02T21:34:38.580Z] 21:34:38     INFO -  /builds/worker/fetches/binutils/bin/ld.bfd: /builds/worker/workspace/obj-build/toolkit/library/gtest/../../../third_party/libwebrtc/common_audio/common_audio_c_gn/Unified_c_common_audio_c_gn0.o: in function `WebRtcSpl_FilterARFastQ12':
[task 2021-11-02T21:34:38.580Z] 21:34:38     INFO -  /builds/worker/checkouts/gecko/third_party/libwebrtc/common_audio/signal_processing/filter_ar_fast_q12.c:22: multiple definition of `WebRtcSpl_FilterARFastQ12'; /builds/worker/workspace/obj-build/toolkit/library/gtest/../../../third_party/libwebrtc/common_audio/common_audio_c_arm_asm_gn/filter_ar_fast_q12_armv7.o:/builds/worker/checkouts/gecko/third_party/libwebrtc/common_audio/signal_processing/filter_ar_fast_q12_armv7.S:43: first defined here
[task 2021-11-02T21:34:38.581Z] 21:34:38     INFO -  /builds/worker/fetches/binutils/bin/ld.bfd: /builds/worker/workspace/obj-build/toolkit/library/gtest/../../../third_party/libwebrtc/common_audio/third_party/spl_sqrt_floor/spl_sqrt_floor_gn/spl_sqrt_floor_arm.o: in function `WebRtcSpl_SqrtFloor':
[task 2021-11-02T21:34:38.581Z] 21:34:38     INFO -  /builds/worker/checkouts/gecko/third_party/libwebrtc/common_audio/third_party/spl_sqrt_floor/spl_sqrt_floor_arm.S:40: multiple definition of `WebRtcSpl_SqrtFloor'; /builds/worker/workspace/obj-build/toolkit/library/gtest/../../../third_party/libwebrtc/common_audio/third_party/spl_sqrt_floor/spl_sqrt_floor_gn/Unified_c_spl_sqrt_floor_gn0.o:/builds/worker/checkouts/gecko/third_party/libwebrtc/common_audio/third_party/spl_sqrt_floor/spl_sqrt_floor.c:59: first defined here
[task 2021-11-02T21:34:38.581Z] 21:34:38     INFO -  /builds/worker/fetches/binutils/bin/ld.bfd: cannot find -landroid_support
[task 2021-11-02T21:34:38.581Z] 21:34:38     INFO -  /builds/worker/fetches/binutils/bin/ld.bfd: cannot find -lunwind

Set release status flags based on info from the regressing bug 1654112

We'll track this in Bug 1738845. I'm almost positive this is due to missing build configs for arm.