the rust build fails on FreeBSD/amd64-14 due to not finding libzstd despite it being installed on the build host.

I tried building rust (on FreeBSD/amd64 14.0) from today's clone (HEAD is 8c39ce5b4fb5b61796e5fd8cec56c7b9abd2122b)

./configure --set install.prefix=$HOME --set install.sysconfdir=$HOME/etc --llvm-root=/usr/local/llvm19
./x.py build

It ended unsuccessfully with the following:

   Compiling rustc_driver v0.0.0 (/home/woods/work/m-rust/compiler/rustc_driver)
error: linking with `cc` failed: exit status: 1
  |
  = note: LC_ALL="C" PATH="/home/woods/work/m-rust/build/x86_64-unknown-freebsd/stage0-sysroot/lib/rustlib/x86_64-unknown-freebsd/bin:/home/woods/work/m-rust/build/x86_64-unknown-freebsd/stage0/lib/rustlib/x86_64-unknown-freebsd/bin:/home/woods/work/m-rust/build/x86_64-unknown-freebsd/stage0/lib/rustlib/x86_64-unknown-freebsd/bin:/home/woods/pkg/bin:/home/woods/bin:/bin:/usr/bin:/usr/local/bin:" VSLANG="1033" "cc" "-Wl,--version-script=/tmp/rustcAGOOXN/list" "-Wl,--no-undefined-version" "-m64" "/tmp/rustcAGOOXN/symbols.o" "<1 object files omitted>" "/home/woods/work/m-rust/build/x86_64-unknown-freebsd/stage0-rustc/x86_64-unknown-freebsd/release/deps/rustc_driver-678ab8838275942c.0bj53j4cvoxvg8zvx88oek9t7.rcgu.rmeta" "<1 object files omitted>" "-Wl,--as-needed" "-Wl,-Bstatic" "/home/woods/work/m-rust/build/x86_64-unknown-freebsd/stage0-rustc/x86_64-unknown-freebsd/release/deps/{librustc_driver_impl-4bae2b5e07e44ec5.rlib,libctrlc-71f931fb16bec6af.rlib,libnix-1442dacdc2c23b79.rlib,librustc_log-c0d6dbecb9cd6dd4.rlib,libtracing_tree-df3639e168c3645e.rlib,libtracing_log-f99def6756aafc8e.rlib,libnu_ansi_term-a98b4f33bd82980a.rlib,libtracing_subscriber-4af61ac18f717d43.rlib,libnu_ansi_term-3b384a8bc7193777.rlib,liboverload-8fc38ace4bb4d4d5.rlib,libsharded_slab-a2f9aa0cd3f25a45.rlib,liblazy_static-914814e95529954b.rlib,libmatchers-067e388262b33701.rlib,libregex_automata-4adedaf6ee0fa036.rlib,libregex_syntax-4c39ade0ad89ae6d.rlib,libthread_local-c4030bc03cb07099.rlib,librustc_smir-94aa48ecbee0c0d4.rlib,libstable_mir-0621e0b5a08f8701.rlib,libtime-d1304a4bb48a1848.rlib,libtime_core-b734096f6ecb5eb5.rlib,libnum_conv-3e0c51cc5fed482c.rlib,libderanged-008beceb12e7b50a.rlib,libpowerfmt-3e9933fe193a019f.rlib,librustc_interface-61ed7d2625417c15.rlib,librustc_codegen_llvm-25c7a8ed8c5465b5.rlib,librustc_llvm-274993179981bcc4.rlib,librustc_sanitizers-d264b09a88f43596.rlib,librustc_hir_typeck-b03ff094e3a2218b.rlib,librustc_hir_analysis-d234234108a003c5.rlib,librustc_monomorphize-c6e8114b8224cda7.rlib,librustc_mir_transform-4e37530aca707852.rlib,librustc_mir_build-9ea12534cbd67e09.rlib,librustc_pattern_analysis-1339abb6211c245e.rlib,librustc_borrowck-9d8433099891f68b.rlib,librustc_traits-958b3148185c2a3c.rlib,librustc_const_eval-c2146265b7408c4d.rlib,librustc_mir_dataflow-2a0f908c13915c17.rlib,librustc_ast_lowering-67063c831bd5d3ab.rlib,librustc_builtin_macros-d22d1eb4f2c29dd5.rlib,librustc_resolve-e53c128ec5f51623.rlib,libpulldown_cmark-68b5c2f2c499d835.rlib,libunicase-8acba8277f961efd.rlib,libpulldown_cmark_escape-723191d07bc8e169.rlib,librustc_passes-319ce4cdcd47d95d.rlib,librustc_privacy-187c6eae831ed696.rlib,librustc_ty_utils-7b4363f085be8f28.rlib,librustc_query_impl-a5f444cae3f476ff.rlib,librustc_lint-45b4eac1ae9f7f25.rlib,libunicode_security-2305730dac9c3b6b.rlib,libunicode_script-ae2a107fc491f12d.rlib,librustc_codegen_ssa-9170e61d173a58b9.rlib,libwasm_encoder-c1005a5681831cf0.rlib,libleb128-4ea5827ad7ab45ca.rlib,libthorin-4836e2f36c09df26.rlib,libhashbrown-acb128d3aafd8e04.rlib,libahash-ca3b6da3e6d427e9.rlib,liballocator_api2-65278355585bae51.rlib,libgimli-754ad356442ad26e.rlib,libfallible_iterator-7b97c71b81546f0e.rlib,librustc_symbol_mangling-aa81523337a2e783.rlib,librustc_demangle-063ce806a6dfa9ed.rlib,libpunycode-9d3c60cfc702bf02.rlib,librustc_trait_selection-b13e11ce3ba168f1.rlib,librustc_next_trait_solver-c705d25318f657cc.rlib,librustc_parse_format-1b833b63b367e737.rlib,librustc_transmute-0a9bc7d98bae3125.rlib,librustc_infer-3f52bd30dec15574.rlib,librustc_incremental-a9515441c3ab6d5c.rlib,libpathdiff-e9ecf6c05ed4f809.rlib,librustc_metadata-3015d800c2ea1fdf.rlib,liblibloading-5e7d99a01c821283.rlib,librustc_expand-595875b815d92e43.rlib,librustc_ast_passes-d41e714d79deacb3.rlib,librustc_parse-e92fc18d31ec22b9.rlib,libunicode_normalization-66e2a5fd6170449c.rlib,libtinyvec-9943206937676f25.rlib,libtinyvec_macros-37be9b660011dd03.rlib}" "/home/woods/work/m-rust/build/x86_64-unknown-freebsd/stage0-sysroot/lib/rustlib/x86_64-unknown-freebsd/lib/{libproc_macro-96ee6d83eae46b34.rlib}" "/home/woods/work/m-rust/build/x86_64-unknown-freebsd/stage0-rustc/x86_64-unknown-freebsd/release/deps/{libregex-2bea9ac640f180bf.rlib,libregex_automata-647e0511891b8f0f.rlib,libaho_corasick-f23555996dc4619d.rlib,libregex_syntax-64253bda1bda70db.rlib,libcc-6e9b4ff5d6443c9f.rlib,libshlex-be60fb23f5fe6fec.rlib,libar_archive_writer-2a8b4e1afb1943a4.rlib,librustc_middle-484b1881b6f3c05c.rlib,libfield_offset-593055940b88c5e9.rlib,libmemoffset-d9b0c3210aca29f5.rlib,librustc_apfloat-4e7872f929d403e9.rlib,libgsgdt-564226be9f7ca74a.rlib,libpolonius_engine-bb3a22c6e2244dca.rlib,libdatafrog-135888ec959203c9.rlib,librustc_query_system-d4ea58f31d4db76b.rlib,librustc_attr_parsing-38c8b27306098089.rlib,librustc_attr_data_structures-65c40a1a6cda555b.rlib,librustc_session-0e9871ae42652270.rlib,libgetopts-27aa0516e322f727.rlib,libunicode_width-bc149f880e63bd63.rlib,librustc_hir_pretty-206eb5f8dd19d9b1.rlib,librustc_errors-f946bf2f8e700c80.rlib,libtermize-ce3ec6ba467a42cd.rlib,librustc_error_codes-b9d8df4e46351aac.rlib,librustc_type_ir-f54c70b1dfc386e8.rlib,librustc_ast_pretty-12b7ff69144951bd.rlib,libitertools-3e3ff0b1c8d4bf49.rlib,libannotate_snippets-9b20301b1b3d9a87.rlib,libanstyle-84c992b12f50dac3.rlib,libtermcolor-654ba8bbb92e5984.rlib,librustc_lint_defs-ea7ebf96a83bb970.rlib,librustc_error_messages-2356bf78fa6678d6.rlib,librustc_baked_icu_data-a98d4ebe25fa9af6.rlib,libicu_list-ac9b7ea4ce1ab578.rlib,libicu_list_data-8ee642e65c15914c.rlib,libregex_automata-cc7a3a7523062e6e.rlib,libicu_provider_adapters-38158b6002458522.rlib,libicu_locid_transform-eec6a847293ac9fc.rlib,libicu_locid_transform_data-825f90b22a433841.rlib,libicu_provider-df9a8027f2c847be.rlib,libicu_locid-78a1a244a3a8ac5b.rlib,liblitemap-93d975e2cd116bb1.rlib,libwriteable-5ae134a171443db4.rlib,libfluent_bundle-4aa5dfb4a552ec40.rlib,libfluent_langneg-7bfa05aa09c9f74a.rlib,libintl_pluralrules-4c1d35599ac487d0.rlib,libself_cell-5d8fd69232569989.rlib,libself_cell-b0ff3ef64a40c698.rlib,libintl_memoizer-2d9750366ebb1874.rlib,libtype_map-3cc803b01bff4da3.rlib,libunic_langid-dceccb47dd44dd89.rlib,libunic_langid_macros-4640b415f304e02a.rlib,libunic_langid_impl-d794a6b3c4630e82.rlib,libtinystr-a57119c43811c860.rlib,libzerovec-beda1b95e521d919.rlib,libyoke-6f7618785e8dbfa2.rlib,libzerofrom-4812fbb32d1507f6.rlib,libfluent_syntax-392311bd6333574a.rlib,libthiserror-37aa34d6eddcecf9.rlib,librustc_hir-71b742c708031fd7.rlib,libodht-ea3cfec055e891b6.rlib,librustc_target-224f6d47fb75a45e.rlib,libobject-39e2d0036a658f7a.rlib,libruzstd-50a940a4324ec02c.rlib,libtwox_hash-82a4ca5450c07ed6.rlib,libstatic_assertions-e68e80149a9f58f3.rlib,libflate2-406a8709afe5980d.rlib,libminiz_oxide-a648d51f161daac9.rlib,libadler2-fb1fb62726045bf1.rlib,libcrc32fast-00805bfffac5de92.rlib,libwasmparser-fdf733c5576d8c4f.rlib,librustc_fs_util-36e75bf255966d88.rlib,librustc_abi-aee6187d68fa8f5c.rlib,librustc_feature-892a64a2c7f3bc8f.rlib,libserde_json-aadd8bc2513e3f81.rlib,libryu-c464a3fbe63b3bcf.rlib,libserde-8d95b7475b55d2a4.rlib,librand_xoshiro-27378eabb6871455.rlib,librand-52d716baae3ac197.rlib,librand_chacha-2b6daeb70e843955.rlib,libppv_lite86-04fe3b6371f86655.rlib,libzerocopy-828797d8768a7475.rlib,libbyteorder-5283af83e54dc47e.rlib,librand_core-d38b5d372c69d418.rlib,librustc_ast-08a251c6832351a6.rlib,libmemchr-0534aa5fd4e2537b.rlib,librustc_ast_ir-382b2f0be9d1f26b.rlib,librustc_lexer-4788e64988e83250.rlib,libunicode_xid-63b77864dd1deb85.rlib,libunicode_properties-954574c360b909b3.rlib,librustc_span-adb841bb52e9683a.rlib,libunicode_width-6c56bd6c6c225ae3.rlib,libblake3-ef07d89ededadc67.rlib,libconstant_time_eq-8211d5e9dcefa3db.rlib,libarrayref-4110a6e4434e2df8.rlib,libitoa-97de34720279d13b.rlib,libscoped_tls-28b3ced1ae35c388.rlib,libsha2-751b38e1ee150a21.rlib,libsha1-73755c23bdb322cf.rlib,libcpufeatures-8f745d695829d317.rlib,libmd5-5d6eead03ad06579.rlib,libdigest-66f3498185594879.rlib,libblock_buffer-7d595291c034ede8.rlib,libcrypto_common-a57783a659a1aff5.rlib,libgeneric_array-353d10e05a4d71a9.rlib,libtypenum-760c1e2613e03e75.rlib,librustc_data_structures-1053647515096a54.rlib,libelsa-8096b935d4697546.rlib,libstable_deref_trait-9712baa2c8bc7388.rlib,libstacker-27c30d4695daed8a.rlib,libpsm-64b545ee7521e23d.rlib,libmemmap2-6adc1efc15a27a67.rlib,librustc_arena-5db0bf02ab8f9233.rlib,libtempfile-bfdefe5410259fda.rlib,libgetrandom-721e4f81a8dd825a.rlib,libfastrand-1fd238d90c73318f.rlib,librustix-44eaff68ea54eb49.rlib,libbitflags-f03bd5a3a2eadeab.rlib,liberrno-e4500660b0f7bbb6.rlib,librustc_stable_hash-b2fef44724b745b4.rlib,libarrayvec-3df6e03caacc1602.rlib,libmeasureme-a11b9e6d02c245b1.rlib,librustc_hash-3a80cf31c5eb998f.rlib,libparking_lot-3f85b0f41caa1d58.rlib,libparking_lot_core-9a1ca066262f7d18.rlib,liblock_api-7b110236eee6ec51.rlib,libscopeguard-dd9f46b9888d511a.rlib,librustc_graphviz-bce1cb9bd7e0b48c.rlib,libjobserver-0906cfd33a10f04e.rlib,libtracing-05e162d36b3dc762.rlib,libcfg_if-93f68ca2cfeae092.rlib,libpin_project_lite-d5321628bd2b0cc8.rlib,libtracing_core-cb13cd587f3cea2d.rlib,libonce_cell-edfc948814f25d31.rlib,librustc_hash-3383be06cb568c81.rlib,librustc_index-3db69d9a816b3639.rlib,librustc_serialize-0839f2b3f7ac629f.rlib,libindexmap-50c421918c915529.rlib,libequivalent-d5de69d1a0ce348b.rlib,librayon-455e3a2ba8168a6c.rlib,librayon_core-617cec76f7e4e92e.rlib,libnum_cpus-0ccb12dbc54ca1bf.rlib,liblibc-9ba6b2a659063125.rlib,libcrossbeam_deque-0ddec9b29b4d9196.rlib,libcrossbeam_epoch-0101bfe3c3ae7290.rlib,libcrossbeam_channel-5e671f5d1760fba6.rlib,libcrossbeam_utils-e6d36c606961ae0b.rlib,libeither-34c50a8e6c5afbec.rlib,libhashbrown-999d4dc558f71ad2.rlib,libfoldhash-c70e8f802b9f757b.rlib,libthin_vec-98e722f8714e6247.rlib,libsmallvec-dc0381fe1ecd023f.rlib,libena-5f114bda1d55ee57.rlib,liblog-bf4c16985b990e5e.rlib}" "/home/woods/work/m-rust/build/x86_64-unknown-freebsd/stage0-sysroot/lib/rustlib/x86_64-unknown-freebsd/lib/{libstd-9922f423544429c4.rlib,libpanic_unwind-a2e9435a70d003be.rlib,libobject-a2cbacc1d9b0cbb6.rlib,libmemchr-abfb5a964f1f530a.rlib,libaddr2line-5fafdcabda5449e2.rlib,libgimli-38f8fa3b8a8c44ee.rlib,librustc_demangle-9295d63a05b32ed3.rlib,libstd_detect-562bc339c6ae89c6.rlib,libhashbrown-94276790940a08b7.rlib,librustc_std_workspace_alloc-d5e9c95677475f2d.rlib,libminiz_oxide-fe15f28d5b78702e.rlib,libadler2-602fd801b8e4808c.rlib,libunwind-557a67c374cbc641.rlib,libcfg_if-d243372002117ff8.rlib,liblibc-7cddd3f0c774adf1.rlib,liballoc-18859d5d405dba87.rlib,librustc_std_workspace_core-7fc511c2f3ba90f3.rlib,libcore-e20f11d3e16bf07e.rlib,libcompiler_builtins-fd24d3e3bbb46650.rlib}" "-Wl,-Bdynamic" "-lPolly" "-lPollyISL" "-lrt" "-lexecinfo" "-lpthread" "-lm" "-lz" "-lzstd" "-lc++" "-lc" "-lrt" "-lutil" "-lexecinfo" "-lkvm" "-lmemstat" "-lkvm" "-lutil" "-lprocstat" "-lrt" "-ldevstat" "-lexecinfo" "-lpthread" "-lgcc_s" "-lc" "-lm" "-lrt" "-lpthread" "-lrt" "-lutil" "-lexecinfo" "-lkvm" "-lmemstat" "-lkvm" "-lutil" "-lprocstat" "-lrt" "-ldevstat" "-Wl,--eh-frame-hdr" "-Wl,-z,noexecstack" "-L" "/home/woods/work/m-rust/build/x86_64-unknown-freebsd/stage0-rustc/x86_64-unknown-freebsd/release/build/psm-436e38c2f952a9a4/out" "-L" "/home/woods/work/m-rust/build/x86_64-unknown-freebsd/stage0-rustc/x86_64-unknown-freebsd/release/build/blake3-c3090fa4edb10df8/out" "-L" "/home/woods/work/m-rust/build/x86_64-unknown-freebsd/stage0-rustc/x86_64-unknown-freebsd/release/build/blake3-c3090fa4edb10df8/out" "-L" "/home/woods/work/m-rust/build/x86_64-unknown-freebsd/stage0-rustc/x86_64-unknown-freebsd/release/build/rustc_llvm-df31628df9f34818/out" "-L" "/usr/local/llvm19/lib" "-o" "/home/woods/work/m-rust/build/x86_64-unknown-freebsd/stage0-rustc/x86_64-unknown-freebsd/release/deps/librustc_driver-678ab8838275942c.so" "-shared" "-Wl,-soname=librustc_driver-678ab8838275942c.so" "-Wl,-z,relro,-z,now" "-Wl,-O1" "-nodefaultlibs" "-Wl,-z,origin" "-Wl,-rpath,$ORIGIN/../lib"
  = note: some arguments are omitted. use `--verbose` to show all linker arguments
  = note: ld: error: unable to find library -lzstd
          cc: error: linker command failed with exit code 1 (use -v to see invocation)
 

Note that zstd is installed:

# pkg info | grep zstd
zstd-1.5.6                     Fast real-time compression algorithm

Obviously the build isn't looking in /usr/local for installed libraries, and I don't see any obvious option in the configure script to tell it either to look there generically by default, or even to look there explicitly for libzstd.

# pkg shlib libzstd.so.1
libzstd.so.1 is provided by the following packages:
zstd-1.5.6
libzstd.so.1 is linked to by the following packages:
llvm15-15.0.7_10
mesa-dri-24.0.7
rsync-3.3.0
tiff-4.4.0_3
binutils-2.43.1,1
llvm19-19.1.6

Perhaps this is one of those intermediate library rpath problems, but anyway, how do I tell x.py to always look in /usr/local for more libraries?

System info:

$ uname -a                                                                                               
FreeBSD fezzik 14.0-RELEASE-p4 FreeBSD 14.0-RELEASE-p4 #0 releng/14.0-4edf3b807: Sat Dec 30 17:43:31 EST 2023     root@worm:/usr/obj/usr/src/amd64.amd64/sys/GENERIC-ZFS amd64

Reproduce the FreeBSD/amd64-14 failure with the reported ./configure options and ./x.py build command. Trace the build configuration and link arguments that produce -lzstd, then verify that a clean Rust build succeeds with libzstd installed on the host.