diff --git a/compiler/rustc_target/src/spec/supported_targets.txt b/compiler/rustc_target/src/spec/supported_targets.txt
new file mode 100644
index 0000000000000..030d611eee5d8
--- /dev/null
+++ b/compiler/rustc_target/src/spec/supported_targets.txt
@@ -0,0 +1,290 @@
+{
+    ("x86_64-unknown-linux-gnu", x86_64_unknown_linux_gnu),
+    ("x86_64-unknown-linux-gnux32", x86_64_unknown_linux_gnux32),
+    ("i686-unknown-linux-gnu", i686_unknown_linux_gnu),
+    ("i586-unknown-linux-gnu", i586_unknown_linux_gnu),
+    ("loongarch64-unknown-linux-gnu", loongarch64_unknown_linux_gnu),
+    ("loongarch64-unknown-linux-musl", loongarch64_unknown_linux_musl),
+    ("m68k-unknown-linux-gnu", m68k_unknown_linux_gnu),
+    ("csky-unknown-linux-gnuabiv2", csky_unknown_linux_gnuabiv2),
+    ("csky-unknown-linux-gnuabiv2hf", csky_unknown_linux_gnuabiv2hf),
+    ("mips-unknown-linux-gnu", mips_unknown_linux_gnu),
+    ("mips64-unknown-linux-gnuabi64", mips64_unknown_linux_gnuabi64),
+    ("mips64el-unknown-linux-gnuabi64", mips64el_unknown_linux_gnuabi64),
+    ("mipsisa32r6-unknown-linux-gnu", mipsisa32r6_unknown_linux_gnu),
+    ("mipsisa32r6el-unknown-linux-gnu", mipsisa32r6el_unknown_linux_gnu),
+    ("mipsisa64r6-unknown-linux-gnuabi64", mipsisa64r6_unknown_linux_gnuabi64),
+    ("mipsisa64r6el-unknown-linux-gnuabi64", mipsisa64r6el_unknown_linux_gnuabi64),
+    ("mipsel-unknown-linux-gnu", mipsel_unknown_linux_gnu),
+    ("powerpc-unknown-linux-gnu", powerpc_unknown_linux_gnu),
+    ("powerpc-unknown-linux-gnuspe", powerpc_unknown_linux_gnuspe),
+    ("powerpc-unknown-linux-musl", powerpc_unknown_linux_musl),
+    ("powerpc64-ibm-aix", powerpc64_ibm_aix),
+    ("powerpc64-unknown-linux-gnu", powerpc64_unknown_linux_gnu),
+    ("powerpc64-unknown-linux-musl", powerpc64_unknown_linux_musl),
+    ("powerpc64le-unknown-linux-gnu", powerpc64le_unknown_linux_gnu),
+    ("powerpc64le-unknown-linux-musl", powerpc64le_unknown_linux_musl),
+    ("s390x-unknown-linux-gnu", s390x_unknown_linux_gnu),
+    ("s390x-unknown-linux-musl", s390x_unknown_linux_musl),
+    ("sparc-unknown-linux-gnu", sparc_unknown_linux_gnu),
+    ("sparc64-unknown-linux-gnu", sparc64_unknown_linux_gnu),
+    ("arm-unknown-linux-gnueabi", arm_unknown_linux_gnueabi),
+    ("arm-unknown-linux-gnueabihf", arm_unknown_linux_gnueabihf),
+    ("armeb-unknown-linux-gnueabi", armeb_unknown_linux_gnueabi),
+    ("arm-unknown-linux-musleabi", arm_unknown_linux_musleabi),
+    ("arm-unknown-linux-musleabihf", arm_unknown_linux_musleabihf),
+    ("armv4t-unknown-linux-gnueabi", armv4t_unknown_linux_gnueabi),
+    ("armv5te-unknown-linux-gnueabi", armv5te_unknown_linux_gnueabi),
+    ("armv5te-unknown-linux-musleabi", armv5te_unknown_linux_musleabi),
+    ("armv5te-unknown-linux-uclibceabi", armv5te_unknown_linux_uclibceabi),
+    ("armv7-unknown-linux-gnueabi", armv7_unknown_linux_gnueabi),
+    ("armv7-unknown-linux-gnueabihf", armv7_unknown_linux_gnueabihf),
+    ("thumbv7neon-unknown-linux-gnueabihf", thumbv7neon_unknown_linux_gnueabihf),
+    ("thumbv7neon-unknown-linux-musleabihf", thumbv7neon_unknown_linux_musleabihf),
+    ("armv7-unknown-linux-musleabi", armv7_unknown_linux_musleabi),
+    ("armv7-unknown-linux-musleabihf", armv7_unknown_linux_musleabihf),
+    ("aarch64-unknown-linux-gnu", aarch64_unknown_linux_gnu),
+    ("aarch64-unknown-linux-musl", aarch64_unknown_linux_musl),
+    ("x86_64-unknown-linux-musl", x86_64_unknown_linux_musl),
+    ("i686-unknown-linux-musl", i686_unknown_linux_musl),
+    ("i586-unknown-linux-musl", i586_unknown_linux_musl),
+    ("mips-unknown-linux-musl", mips_unknown_linux_musl),
+    ("mipsel-unknown-linux-musl", mipsel_unknown_linux_musl),
+    ("mips64-unknown-linux-muslabi64", mips64_unknown_linux_muslabi64),
+    ("mips64el-unknown-linux-muslabi64", mips64el_unknown_linux_muslabi64),
+    ("hexagon-unknown-linux-musl", hexagon_unknown_linux_musl),
+    ("hexagon-unknown-none-elf", hexagon_unknown_none_elf),
+
+    ("mips-unknown-linux-uclibc", mips_unknown_linux_uclibc),
+    ("mipsel-unknown-linux-uclibc", mipsel_unknown_linux_uclibc),
+
+    ("i686-linux-android", i686_linux_android),
+    ("x86_64-linux-android", x86_64_linux_android),
+    ("arm-linux-androideabi", arm_linux_androideabi),
+    ("armv7-linux-androideabi", armv7_linux_androideabi),
+    ("thumbv7neon-linux-androideabi", thumbv7neon_linux_androideabi),
+    ("aarch64-linux-android", aarch64_linux_android),
+    ("riscv64-linux-android", riscv64_linux_android),
+
+    ("aarch64-unknown-freebsd", aarch64_unknown_freebsd),
+    ("armv6-unknown-freebsd", armv6_unknown_freebsd),
+    ("armv7-unknown-freebsd", armv7_unknown_freebsd),
+    ("i686-unknown-freebsd", i686_unknown_freebsd),
+    ("powerpc-unknown-freebsd", powerpc_unknown_freebsd),
+    ("powerpc64-unknown-freebsd", powerpc64_unknown_freebsd),
+    ("powerpc64le-unknown-freebsd", powerpc64le_unknown_freebsd),
+    ("riscv64gc-unknown-freebsd", riscv64gc_unknown_freebsd),
+    ("x86_64-unknown-freebsd", x86_64_unknown_freebsd),
+
+    ("x86_64-unknown-dragonfly", x86_64_unknown_dragonfly),
+
+    ("aarch64-unknown-openbsd", aarch64_unknown_openbsd),
+    ("i686-unknown-openbsd", i686_unknown_openbsd),
+    ("powerpc-unknown-openbsd", powerpc_unknown_openbsd),
+    ("powerpc64-unknown-openbsd", powerpc64_unknown_openbsd),
+    ("riscv64gc-unknown-openbsd", riscv64gc_unknown_openbsd),
+    ("sparc64-unknown-openbsd", sparc64_unknown_openbsd),
+    ("x86_64-unknown-openbsd", x86_64_unknown_openbsd),
+
+    ("aarch64-unknown-netbsd", aarch64_unknown_netbsd),
+    ("aarch64_be-unknown-netbsd", aarch64_be_unknown_netbsd),
+    ("armv6-unknown-netbsd-eabihf", armv6_unknown_netbsd_eabihf),
+    ("armv7-unknown-netbsd-eabihf", armv7_unknown_netbsd_eabihf),
+    ("i586-unknown-netbsd", i586_unknown_netbsd),
+    ("i686-unknown-netbsd", i686_unknown_netbsd),
+    ("mipsel-unknown-netbsd", mipsel_unknown_netbsd),
+    ("powerpc-unknown-netbsd", powerpc_unknown_netbsd),
+    ("riscv64gc-unknown-netbsd", riscv64gc_unknown_netbsd),
+    ("sparc64-unknown-netbsd", sparc64_unknown_netbsd),
+    ("x86_64-unknown-netbsd", x86_64_unknown_netbsd),
+
+    ("i686-unknown-haiku", i686_unknown_haiku),
+    ("x86_64-unknown-haiku", x86_64_unknown_haiku),
+
+    ("i686-unknown-hurd-gnu", i686_unknown_hurd_gnu),
+
+    ("aarch64-apple-darwin", aarch64_apple_darwin),
+    ("arm64e-apple-darwin", arm64e_apple_darwin),
+    ("x86_64-apple-darwin", x86_64_apple_darwin),
+    ("x86_64h-apple-darwin", x86_64h_apple_darwin),
+    ("i686-apple-darwin", i686_apple_darwin),
+
+    // FIXME(#106649): Remove aarch64-fuchsia in favor of aarch64-unknown-fuchsia
+    ("aarch64-fuchsia", aarch64_fuchsia),
+    ("aarch64-unknown-fuchsia", aarch64_unknown_fuchsia),
+    ("riscv64gc-unknown-fuchsia", riscv64gc_unknown_fuchsia),
+    // FIXME(#106649): Remove x86_64-fuchsia in favor of x86_64-unknown-fuchsia
+    ("x86_64-fuchsia", x86_64_fuchsia),
+    ("x86_64-unknown-fuchsia", x86_64_unknown_fuchsia),
+
+    ("avr-unknown-gnu-atmega328", avr_unknown_gnu_atmega328),
+
+    ("x86_64-unknown-l4re-uclibc", x86_64_unknown_l4re_uclibc),
+
+    ("aarch64-unknown-redox", aarch64_unknown_redox),
+    ("x86_64-unknown-redox", x86_64_unknown_redox),
+
+    ("i386-apple-ios", i386_apple_ios),
+    ("x86_64-apple-ios", x86_64_apple_ios),
+    ("aarch64-apple-ios", aarch64_apple_ios),
+    ("arm64e-apple-ios", arm64e_apple_ios),
+    ("armv7s-apple-ios", armv7s_apple_ios),
+    ("x86_64-apple-ios-macabi", x86_64_apple_ios_macabi),
+    ("aarch64-apple-ios-macabi", aarch64_apple_ios_macabi),
+    ("aarch64-apple-ios-sim", aarch64_apple_ios_sim),
+    ("aarch64-apple-tvos", aarch64_apple_tvos),
+    ("aarch64-apple-tvos-sim", aarch64_apple_tvos_sim),
+    ("x86_64-apple-tvos", x86_64_apple_tvos),
+
+    ("armv7k-apple-watchos", armv7k_apple_watchos),
+    ("arm64_32-apple-watchos", arm64_32_apple_watchos),
+    ("x86_64-apple-watchos-sim", x86_64_apple_watchos_sim),
+    ("aarch64-apple-watchos", aarch64_apple_watchos),
+    ("aarch64-apple-watchos-sim", aarch64_apple_watchos_sim),
+
+    ("armebv7r-none-eabi", armebv7r_none_eabi),
+    ("armebv7r-none-eabihf", armebv7r_none_eabihf),
+    ("armv7r-none-eabi", armv7r_none_eabi),
+    ("armv7r-none-eabihf", armv7r_none_eabihf),
+    ("armv8r-none-eabihf", armv8r_none_eabihf),
+
+    ("x86_64-pc-solaris", x86_64_pc_solaris),
+    ("sparcv9-sun-solaris", sparcv9_sun_solaris),
+
+    ("x86_64-unknown-illumos", x86_64_unknown_illumos),
+    ("aarch64-unknown-illumos", aarch64_unknown_illumos),
+
+    ("x86_64-pc-windows-gnu", x86_64_pc_windows_gnu),
+    ("i686-pc-windows-gnu", i686_pc_windows_gnu),
+    ("i686-uwp-windows-gnu", i686_uwp_windows_gnu),
+    ("x86_64-uwp-windows-gnu", x86_64_uwp_windows_gnu),
+
+    ("aarch64-pc-windows-gnullvm", aarch64_pc_windows_gnullvm),
+    ("i686-pc-windows-gnullvm", i686_pc_windows_gnullvm),
+    ("x86_64-pc-windows-gnullvm", x86_64_pc_windows_gnullvm),
+
+    ("aarch64-pc-windows-msvc", aarch64_pc_windows_msvc),
+    ("aarch64-uwp-windows-msvc", aarch64_uwp_windows_msvc),
+    ("arm64ec-pc-windows-msvc", arm64ec_pc_windows_msvc),
+    ("x86_64-pc-windows-msvc", x86_64_pc_windows_msvc),
+    ("x86_64-uwp-windows-msvc", x86_64_uwp_windows_msvc),
+    ("x86_64-win7-windows-msvc", x86_64_win7_windows_msvc),
+    ("i686-pc-windows-msvc", i686_pc_windows_msvc),
+    ("i686-uwp-windows-msvc", i686_uwp_windows_msvc),
+    ("i686-win7-windows-msvc", i686_win7_windows_msvc),
+    ("i586-pc-windows-msvc", i586_pc_windows_msvc),
+    ("thumbv7a-pc-windows-msvc", thumbv7a_pc_windows_msvc),
+    ("thumbv7a-uwp-windows-msvc", thumbv7a_uwp_windows_msvc),
+
+    ("wasm32-unknown-emscripten", wasm32_unknown_emscripten),
+    ("wasm32-unknown-unknown", wasm32_unknown_unknown),
+    ("wasm32-wasi", wasm32_wasi),
+    ("wasm32-wasip1", wasm32_wasip1),
+    ("wasm32-wasip2", wasm32_wasip2),
+    ("wasm32-wasip1-threads", wasm32_wasip1_threads),
+    ("wasm64-unknown-unknown", wasm64_unknown_unknown),
+
+    ("thumbv6m-none-eabi", thumbv6m_none_eabi),
+    ("thumbv7m-none-eabi", thumbv7m_none_eabi),
+    ("thumbv7em-none-eabi", thumbv7em_none_eabi),
+    ("thumbv7em-none-eabihf", thumbv7em_none_eabihf),
+    ("thumbv8m.base-none-eabi", thumbv8m_base_none_eabi),
+    ("thumbv8m.main-none-eabi", thumbv8m_main_none_eabi),
+    ("thumbv8m.main-none-eabihf", thumbv8m_main_none_eabihf),
+
+    ("armv7a-none-eabi", armv7a_none_eabi),
+    ("armv7a-none-eabihf", armv7a_none_eabihf),
+
+    ("msp430-none-elf", msp430_none_elf),
+
+    ("aarch64-unknown-hermit", aarch64_unknown_hermit),
+    ("riscv64gc-unknown-hermit", riscv64gc_unknown_hermit),
+    ("x86_64-unknown-hermit", x86_64_unknown_hermit),
+
+    ("x86_64-unikraft-linux-musl", x86_64_unikraft_linux_musl),
+
+    ("riscv32i-unknown-none-elf", riscv32i_unknown_none_elf),
+    ("riscv32im-risc0-zkvm-elf", riscv32im_risc0_zkvm_elf),
+    ("riscv32im-unknown-none-elf", riscv32im_unknown_none_elf),
+    ("riscv32ima-unknown-none-elf", riscv32ima_unknown_none_elf),
+    ("riscv32imc-unknown-none-elf", riscv32imc_unknown_none_elf),
+    ("riscv32imc-esp-espidf", riscv32imc_esp_espidf),
+    ("riscv32imac-esp-espidf", riscv32imac_esp_espidf),
+    ("riscv32imafc-esp-espidf", riscv32imafc_esp_espidf),
+
+    ("riscv32imac-unknown-none-elf", riscv32imac_unknown_none_elf),
+    ("riscv32imafc-unknown-none-elf", riscv32imafc_unknown_none_elf),
+    ("riscv32imac-unknown-xous-elf", riscv32imac_unknown_xous_elf),
+    ("riscv32gc-unknown-linux-gnu", riscv32gc_unknown_linux_gnu),
+    ("riscv32gc-unknown-linux-musl", riscv32gc_unknown_linux_musl),
+    ("riscv64imac-unknown-none-elf", riscv64imac_unknown_none_elf),
+    ("riscv64gc-unknown-none-elf", riscv64gc_unknown_none_elf),
+    ("riscv64gc-unknown-linux-gnu", riscv64gc_unknown_linux_gnu),
+    ("riscv64gc-unknown-linux-musl", riscv64gc_unknown_linux_musl),
+
+    ("sparc-unknown-none-elf", sparc_unknown_none_elf),
+
+    ("loongarch64-unknown-none", loongarch64_unknown_none),
+    ("loongarch64-unknown-none-softfloat", loongarch64_unknown_none_softfloat),
+
+    ("aarch64-unknown-none", aarch64_unknown_none),
+    ("aarch64-unknown-none-softfloat", aarch64_unknown_none_softfloat),
+
+    ("x86_64-fortanix-unknown-sgx", x86_64_fortanix_unknown_sgx),
+
+    ("x86_64-unknown-uefi", x86_64_unknown_uefi),
+    ("i686-unknown-uefi", i686_unknown_uefi),
+    ("aarch64-unknown-uefi", aarch64_unknown_uefi),
+
+    ("nvptx64-nvidia-cuda", nvptx64_nvidia_cuda),
+
+    ("i686-wrs-vxworks", i686_wrs_vxworks),
+    ("x86_64-wrs-vxworks", x86_64_wrs_vxworks),
+    ("armv7-wrs-vxworks-eabihf", armv7_wrs_vxworks_eabihf),
+    ("aarch64-wrs-vxworks", aarch64_wrs_vxworks),
+    ("powerpc-wrs-vxworks", powerpc_wrs_vxworks),
+    ("powerpc-wrs-vxworks-spe", powerpc_wrs_vxworks_spe),
+    ("powerpc64-wrs-vxworks", powerpc64_wrs_vxworks),
+
+    ("aarch64-kmc-solid_asp3", aarch64_kmc_solid_asp3),
+    ("armv7a-kmc-solid_asp3-eabi", armv7a_kmc_solid_asp3_eabi),
+    ("armv7a-kmc-solid_asp3-eabihf", armv7a_kmc_solid_asp3_eabihf),
+
+    ("mipsel-sony-psp", mipsel_sony_psp),
+    ("mipsel-sony-psx", mipsel_sony_psx),
+    ("mipsel-unknown-none", mipsel_unknown_none),
+    ("thumbv4t-none-eabi", thumbv4t_none_eabi),
+    ("armv4t-none-eabi", armv4t_none_eabi),
+    ("thumbv5te-none-eabi", thumbv5te_none_eabi),
+    ("armv5te-none-eabi", armv5te_none_eabi),
+
+    ("aarch64_be-unknown-linux-gnu", aarch64_be_unknown_linux_gnu),
+    ("aarch64-unknown-linux-gnu_ilp32", aarch64_unknown_linux_gnu_ilp32),
+    ("aarch64_be-unknown-linux-gnu_ilp32", aarch64_be_unknown_linux_gnu_ilp32),
+
+    ("bpfeb-unknown-none", bpfeb_unknown_none),
+    ("bpfel-unknown-none", bpfel_unknown_none),
+
+    ("armv6k-nintendo-3ds", armv6k_nintendo_3ds),
+
+    ("aarch64-nintendo-switch-freestanding", aarch64_nintendo_switch_freestanding),
+
+    ("armv7-sony-vita-newlibeabihf", armv7_sony_vita_newlibeabihf),
+
+    ("armv7-unknown-linux-uclibceabi", armv7_unknown_linux_uclibceabi),
+    ("armv7-unknown-linux-uclibceabihf", armv7_unknown_linux_uclibceabihf),
+
+    ("x86_64-unknown-none", x86_64_unknown_none),
+
+    ("aarch64-unknown-teeos", aarch64_unknown_teeos),
+
+    ("mips64-openwrt-linux-musl", mips64_openwrt_linux_musl),
+
+    ("aarch64-unknown-nto-qnx710", aarch64_unknown_nto_qnx710),
+    ("x86_64-pc-nto-qnx710", x86_64_pc_nto_qnx710),
+    ("i586-pc-nto-qnx700", i586_pc_nto_qnx700),
+
+    ("aarch64-unknown-linux-ohos", aarch64_unknown_linux_ohos),
+    ("armv7-unknown-linux-ohos", armv7_unknown_linux_ohos),
+    ("x86_64-unknown-linux-ohos", x86_64_unknown_linux_ohos),
+}
\ No newline at end of file
diff --git a/src/bootstrap/src/core/sanity.rs b/src/bootstrap/src/core/sanity.rs
index e03b1e179084e..ea29885042744 100644
--- a/src/bootstrap/src/core/sanity.rs
+++ b/src/bootstrap/src/core/sanity.rs
@@ -177,6 +177,29 @@ than building it.
             continue;
         }
 
+        // Check if there exists a built-in target in the list of supported targets.
+        let mut has_target = false;
+
+        let cur_dir = build.config.src.display().to_string();
+        
+        let supported_target_file = format!("{cur_dir}/compiler/rustc_target/src/spec/supported_targets.txt");
+        let contents = fs::read_to_string(supported_target_file)
+            .expect("Should have been able to read the file.");
+
+        let target_str = target.to_string();
+        for line in contents.lines() {
+            has_target |= line.contains(&target_str);
+        }
+
+        // If not, check for a valid file location that may have been specified 
+        // by the user for the custom target.
+        has_target |= env::var_os("RUST_TARGET_PATH").is_some();
+
+        if !has_target {
+            panic!("No such target exists in the target list, 
+                specify a correct location of the JSON specification file for custom targets!")
+        }
+
         if !build.config.dry_run() {
             cmd_finder.must_have(build.cc(*target));
             if let Some(ar) = build.ar(*target) {