Just out of curiosity, is it a Mac M1 (ARM64) ?

No no, you're welcome ;-)

i use a MacBook Pro mi-2010
with 2,4 GHz Intel Core 2 Duo (P8600).

Yes, why the linker say :
(maybe you meant: _php_addslashes_default, _php_addslashes_sse42 )
Like the compil create sse42, avx2, ssse3 functions versions ?

It works even tough not necessarily directly. It is possible to take inspiration from homebrew for example https://github.com/Homebrew/homebrew-core/blob/master/Formula/php.rb ; I personally use a script to set all environment variables before build.

With the last version 8.0.3, i've the same make error :
---
Undefined symbols for architecture x86_64:
  "_php_addslashes", referenced from:
      _php_filter_add_slashes in sanitizing_filters.o
      _zif_addslashes in string.o
      _zif_stream_socket_client in streamsfuncs.o
     (maybe you meant: _php_addslashes_default, _php_addslashes_sse42 )
  "_php_base64_decode_ex", referenced from:
      _to_zval_base64 in php_encoding.o
      _zif_base64_decode in base64.o
      _php_handle_auth_data in main.o
      _php_stream_url_wrap_rfc2397 in memory.o
     (maybe you meant: _php_base64_decode_ex_avx2, _php_base64_decode_ex_default , _php_base64_decode_ex_ssse3 )
  "_php_base64_encode", referenced from:
      _to_xml_base64 in php_encoding.o
      _proxy_authentication in php_http.o
      _basic_authentication in php_http.o
      _make_http_soap_request in php_http.o
      _zif_base64_encode in base64.o
      _php_stream_url_wrap_http_ex in http_fopen_wrapper.o
      _php_password_bcrypt_hash in password.o
      ...
     (maybe you meant: _php_base64_encode_default, _php_base64_encode_ssse3 , _php_base64_encode_avx2 )
  "_php_stripslashes", referenced from:
      _zif_stripslashes in string.o
     (maybe you meant: _php_stripslashes_sse42, _php_stripslashes_default )
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make: *** [libs/libphp.bundle] Error 1
---

If someone understand why this error block the compilation ?!

Is there anybody here ?

I am seeing exactly the same problem. 
PHP 8.0.3
Libsodium 1.0.18
OS X 11.2.3 (on Intel, not M1)

Libsodium compiled with : ./configure --prefix=/Users/foo/bar/php/build

I am trying to compile PHP using:
 env LIBSODIUM_CFLAGS='-I/Users/foo/bar/php/build/include/' LIBSODIUM_LIBS='-L/Users/foo/bar/php/build/lib/' DYLD_FALLBACK_LIBRARY_PATH='/Users/foo/bar/php/build/lib' ./configure --prefix=/Users/bp/Work/php/build --without-libxml --without-sqlite3 --disable-dom --without-iconv --without-pdo-sqlite --disable-simplexml --disable-xml --disable-xmlreader --disable-xmlwriter --with-sodium

I get the following:
Undefined symbols for architecture x86_64:
  "_crypto_aead_aes256gcm_decrypt", referenced from:
      _zif_sodium_crypto_aead_aes256gcm_decrypt in libsodium.o
     (maybe you meant: _zif_sodium_crypto_aead_aes256gcm_decrypt)
  "_crypto_aead_aes256gcm_encrypt", referenced from:
      _zif_sodium_crypto_aead_aes256gcm_encrypt in libsodium.o
     (maybe you meant: _zif_sodium_crypto_aead_aes256gcm_encrypt)
  "_crypto_aead_aes256gcm_is_available", referenced from:
      _zif_sodium_crypto_aead_aes256gcm_is_available in libsodium.o
     (maybe you meant: _zif_sodium_crypto_aead_aes256gcm_is_available)
  "_crypto_aead_chacha20poly1305_decrypt", referenced from:
      _zif_sodium_crypto_aead_chacha20poly1305_decrypt in libsodium.o
     (maybe you meant: _zif_sodium_crypto_aead_chacha20poly1305_decrypt)
  "_crypto_aead_chacha20poly1305_encrypt", referenced from:
      _zif_sodium_crypto_aead_chacha20poly1305_encrypt in libsodium.o
     (maybe you meant: _zif_sodium_crypto_aead_chacha20poly1305_encrypt)
  "_crypto_aead_chacha20poly1305_ietf_decrypt", referenced from:
      _zif_sodium_crypto_aead_chacha20poly1305_ietf_decrypt in libsodium.o
     (maybe you meant: _zif_sodium_crypto_aead_chacha20poly1305_ietf_decrypt)
  "_crypto_aead_chacha20poly1305_ietf_encrypt", referenced from:
      _zif_sodium_crypto_aead_chacha20poly1305_ietf_encrypt in libsodium.o
     (maybe you meant: _zif_sodium_crypto_aead_chacha20poly1305_ietf_encrypt)
  "_crypto_aead_xchacha20poly1305_ietf_decrypt", referenced from:
      _zif_sodium_crypto_aead_xchacha20poly1305_ietf_decrypt in libsodium.o
     (maybe you meant: _zif_sodium_crypto_aead_xchacha20poly1305_ietf_decrypt)
  "_crypto_aead_xchacha20poly1305_ietf_encrypt", referenced from:
      _zif_sodium_crypto_aead_xchacha20poly1305_ietf_encrypt in libsodium.o
     (maybe you meant: _zif_sodium_crypto_aead_xchacha20poly1305_ietf_encrypt)
  "_crypto_auth", referenced from:
      _zif_sodium_crypto_auth in libsodium.o
     (maybe you meant: _zif_sodium_crypto_auth, _zif_sodium_crypto_auth_keygen , _zif_sodium_crypto_auth_verify )
  "_crypto_auth_verify", referenced from:
      _zif_sodium_crypto_auth_verify in libsodium.o
     (maybe you meant: _zif_sodium_crypto_auth_verify)
  "_crypto_box_easy", referenced from:
      _zif_sodium_crypto_box in libsodium.o
  "_crypto_box_keypair", referenced from:
      _zif_sodium_crypto_box_keypair in libsodium.o
     (maybe you meant: _zif_sodium_crypto_box_keypair_from_secretkey_and_publickey, _zif_sodium_crypto_box_keypair )
  "_crypto_box_open_easy", referenced from:
      _zif_sodium_crypto_box_open in libsodium.o
  "_crypto_box_seal", referenced from:
      _zif_sodium_crypto_box_seal in libsodium.o
     (maybe you meant: _zif_sodium_crypto_box_seal_open, _zif_sodium_crypto_box_seal )
  "_crypto_box_seal_open", referenced from:
      _zif_sodium_crypto_box_seal_open in libsodium.o
     (maybe you meant: _zif_sodium_crypto_box_seal_open)
  "_crypto_box_seed_keypair", referenced from:
      _zif_sodium_crypto_box_seed_keypair in libsodium.o
     (maybe you meant: _zif_sodium_crypto_box_seed_keypair)
  "_crypto_generichash", referenced from:
      _zif_sodium_crypto_generichash in libsodium.o
      _zif_sodium_crypto_kx_seed_keypair in libsodium.o
     (maybe you meant: _zif_sodium_crypto_generichash_init, _zif_sodium_crypto_generichash , _zif_sodium_crypto_generichash_keygen , _zif_sodium_crypto_generichash_update , _zif_sodium_crypto_generichash_final )
  "_crypto_generichash_final", referenced from:
      _zif_sodium_crypto_generichash_final in libsodium.o
      _zif_sodium_crypto_kx_client_session_keys in libsodium.o
      _zif_sodium_crypto_kx_server_session_keys in libsodium.o
     (maybe you meant: _zif_sodium_crypto_generichash_final)
  "_crypto_generichash_init", referenced from:
      _zif_sodium_crypto_generichash_init in libsodium.o
      _zif_sodium_crypto_kx_client_session_keys in libsodium.o
      _zif_sodium_crypto_kx_server_session_keys in libsodium.o
     (maybe you meant: _zif_sodium_crypto_generichash_init)
  "_crypto_generichash_update", referenced from:
      _zif_sodium_crypto_generichash_update in libsodium.o
      _zif_sodium_crypto_kx_client_session_keys in libsodium.o
      _zif_sodium_crypto_kx_server_session_keys in libsodium.o
     (maybe you meant: _zif_sodium_crypto_generichash_update)
  "_crypto_kdf_derive_from_key", referenced from:
      _zif_sodium_crypto_kdf_derive_from_key in libsodium.o
     (maybe you meant: _zif_sodium_crypto_kdf_derive_from_key)
  "_crypto_pwhash", referenced from:
      _zif_sodium_crypto_pwhash in libsodium.o
     (maybe you meant: _zif_sodium_crypto_pwhash_scryptsalsa208sha256_str_verify, _zif_sodium_crypto_pwhash_str_verify , _zif_sodium_crypto_pwhash_str_needs_rehash , _zif_sodium_crypto_pwhash_scryptsalsa208sha256 , _zif_sodium_crypto_pwhash , _zif_sodium_crypto_pwhash_scryptsalsa208sha256_str , _zif_sodium_crypto_pwhash_str )
  "_crypto_pwhash_argon2id", referenced from:
      _zif_sodium_crypto_pwhash in libsodium.o
  "_crypto_pwhash_memlimit_interactive", referenced from:
      _zm_startup_sodium in libsodium.o
  "_crypto_pwhash_memlimit_moderate", referenced from:
      _zm_startup_sodium in libsodium.o
  "_crypto_pwhash_memlimit_sensitive", referenced from:
      _zm_startup_sodium in libsodium.o
  "_crypto_pwhash_opslimit_interactive", referenced from:
      _zm_startup_sodium in libsodium.o
  "_crypto_pwhash_opslimit_moderate", referenced from:
      _zm_startup_sodium in libsodium.o
  "_crypto_pwhash_opslimit_sensitive", referenced from:
      _zm_startup_sodium in libsodium.o
  "_crypto_pwhash_scryptsalsa208sha256", referenced from:
      _zif_sodium_crypto_pwhash_scryptsalsa208sha256 in libsodium.o
     (maybe you meant: _zif_sodium_crypto_pwhash_scryptsalsa208sha256_str_verify, _zif_sodium_crypto_pwhash_scryptsalsa208sha256 , _zif_sodium_crypto_pwhash_scryptsalsa208sha256_str )
  "_crypto_pwhash_scryptsalsa208sha256_memlimit_interactive", referenced from:
      _zm_startup_sodium in libsodium.o
  "_crypto_pwhash_scryptsalsa208sha256_memlimit_sensitive", referenced from:
      _zm_startup_sodium in libsodium.o
  "_crypto_pwhash_scryptsalsa208sha256_opslimit_interactive", referenced from:
      _zm_startup_sodium in libsodium.o
  "_crypto_pwhash_scryptsalsa208sha256_opslimit_sensitive", referenced from:
      _zm_startup_sodium in libsodium.o
  "_crypto_pwhash_scryptsalsa208sha256_str", referenced from:
      _zif_sodium_crypto_pwhash_scryptsalsa208sha256_str in libsodium.o
     (maybe you meant: _zif_sodium_crypto_pwhash_scryptsalsa208sha256_str_verify, _zif_sodium_crypto_pwhash_scryptsalsa208sha256_str )
  "_crypto_pwhash_scryptsalsa208sha256_str_verify", referenced from:
      _zif_sodium_crypto_pwhash_scryptsalsa208sha256_str_verify in libsodium.o
     (maybe you meant: _zif_sodium_crypto_pwhash_scryptsalsa208sha256_str_verify)
  "_crypto_pwhash_str", referenced from:
      _zif_sodium_crypto_pwhash_str in libsodium.o
     (maybe you meant: _zif_sodium_crypto_pwhash_str_verify, _zif_sodium_crypto_pwhash_str_needs_rehash , _zif_sodium_crypto_pwhash_str )
  "_crypto_pwhash_str_alg", referenced from:
      _php_sodium_argon2_hash in sodium_pwhash.o
  "_crypto_pwhash_str_needs_rehash", referenced from:
      _zif_sodium_crypto_pwhash_str_needs_rehash in libsodium.o
      _php_sodium_argon2_needs_rehash in sodium_pwhash.o
     (maybe you meant: _zif_sodium_crypto_pwhash_str_needs_rehash)
  "_crypto_pwhash_str_verify", referenced from:
      _zif_sodium_crypto_pwhash_str_verify in libsodium.o
      _php_sodium_argon2_verify in sodium_pwhash.o
     (maybe you meant: _zif_sodium_crypto_pwhash_str_verify)
  "_crypto_scalarmult", referenced from:
      _zif_sodium_crypto_scalarmult in libsodium.o
      _zif_sodium_crypto_kx_client_session_keys in libsodium.o
      _zif_sodium_crypto_kx_server_session_keys in libsodium.o
     (maybe you meant: _zif_sodium_crypto_scalarmult)
  "_crypto_scalarmult_base", referenced from:
      _zif_sodium_crypto_box_publickey_from_secretkey in libsodium.o
      _zif_sodium_crypto_kx_seed_keypair in libsodium.o
      _zif_sodium_crypto_kx_keypair in libsodium.o
  "_crypto_secretbox_easy", referenced from:
      _zif_sodium_crypto_secretbox in libsodium.o
  "_crypto_secretbox_open_easy", referenced from:
      _zif_sodium_crypto_secretbox_open in libsodium.o
  "_crypto_secretstream_xchacha20poly1305_init_pull", referenced from:
      _zif_sodium_crypto_secretstream_xchacha20poly1305_init_pull in libsodium.o
     (maybe you meant: _zif_sodium_crypto_secretstream_xchacha20poly1305_init_pull)
  "_crypto_secretstream_xchacha20poly1305_init_push", referenced from:
      _zif_sodium_crypto_secretstream_xchacha20poly1305_init_push in libsodium.o
     (maybe you meant: _zif_sodium_crypto_secretstream_xchacha20poly1305_init_push)
  "_crypto_secretstream_xchacha20poly1305_pull", referenced from:
      _zif_sodium_crypto_secretstream_xchacha20poly1305_pull in libsodium.o
     (maybe you meant: _zif_sodium_crypto_secretstream_xchacha20poly1305_pull)
  "_crypto_secretstream_xchacha20poly1305_push", referenced from:
      _zif_sodium_crypto_secretstream_xchacha20poly1305_push in libsodium.o
     (maybe you meant: _zif_sodium_crypto_secretstream_xchacha20poly1305_push)
  "_crypto_secretstream_xchacha20poly1305_rekey", referenced from:
      _zif_sodium_crypto_secretstream_xchacha20poly1305_rekey in libsodium.o
     (maybe you meant: _zif_sodium_crypto_secretstream_xchacha20poly1305_rekey)
  "_crypto_shorthash", referenced from:
      _zif_sodium_crypto_shorthash in libsodium.o
     (maybe you meant: _zif_sodium_crypto_shorthash_keygen, _zif_sodium_crypto_shorthash )
  "_crypto_sign", referenced from:
      _zif_sodium_crypto_sign in libsodium.o
     (maybe you meant: _zif_sodium_crypto_sign_keypair_from_secretkey_and_publickey, _zif_sodium_crypto_sign_ed25519_pk_to_curve25519 , _zif_sodium_crypto_sign_ed25519_sk_to_curve25519 , _zif_sodium_crypto_sign_open , _zif_sodium_crypto_sign , _zif_sodium_crypto_sign_seed_keypair , _zif_sodium_crypto_sign_keypair , _zif_sodium_crypto_sign_detached , _zif_sodium_crypto_sign_verify_detached , _zif_sodium_crypto_sign_publickey , _zif_sodium_crypto_sign_secretkey , _zif_sodium_crypto_sign_publickey_from_secretkey )
  "_crypto_sign_detached", referenced from:
      _zif_sodium_crypto_sign_detached in libsodium.o
     (maybe you meant: _zif_sodium_crypto_sign_detached)
  "_crypto_sign_ed25519_pk_to_curve25519", referenced from:
      _zif_sodium_crypto_sign_ed25519_pk_to_curve25519 in libsodium.o
     (maybe you meant: _zif_sodium_crypto_sign_ed25519_pk_to_curve25519)
  "_crypto_sign_ed25519_sk_to_curve25519", referenced from:
      _zif_sodium_crypto_sign_ed25519_sk_to_curve25519 in libsodium.o
     (maybe you meant: _zif_sodium_crypto_sign_ed25519_sk_to_curve25519)
  "_crypto_sign_ed25519_sk_to_pk", referenced from:
      _zif_sodium_crypto_sign_publickey_from_secretkey in libsodium.o
  "_crypto_sign_keypair", referenced from:
      _zif_sodium_crypto_sign_keypair in libsodium.o
     (maybe you meant: _zif_sodium_crypto_sign_keypair_from_secretkey_and_publickey, _zif_sodium_crypto_sign_keypair )
  "_crypto_sign_open", referenced from:
      _zif_sodium_crypto_sign_open in libsodium.o
     (maybe you meant: _zif_sodium_crypto_sign_open)
  "_crypto_sign_seed_keypair", referenced from:
      _zif_sodium_crypto_sign_seed_keypair in libsodium.o
     (maybe you meant: _zif_sodium_crypto_sign_seed_keypair)
  "_crypto_sign_verify_detached", referenced from:
      _zif_sodium_crypto_sign_verify_detached in libsodium.o
     (maybe you meant: _zif_sodium_crypto_sign_verify_detached)
  "_crypto_stream", referenced from:
      _zif_sodium_crypto_stream in libsodium.o
     (maybe you meant: _zif_sodium_crypto_stream_keygen, _zif_sodium_crypto_stream_xor , _zif_sodium_crypto_stream )
  "_crypto_stream_xor", referenced from:
      _zif_sodium_crypto_stream_xor in libsodium.o
     (maybe you meant: _zif_sodium_crypto_stream_xor)
  "_randombytes_buf", referenced from:
      _zif_sodium_crypto_kx_keypair in libsodium.o
      _zif_sodium_crypto_aead_aes256gcm_keygen in libsodium.o
      _zif_sodium_crypto_aead_chacha20poly1305_keygen in libsodium.o
      _zif_sodium_crypto_aead_chacha20poly1305_ietf_keygen in libsodium.o
      _zif_sodium_crypto_aead_xchacha20poly1305_ietf_keygen in libsodium.o
      _zif_sodium_crypto_auth_keygen in libsodium.o
      _zif_sodium_crypto_generichash_keygen in libsodium.o
      ...
  "_randombytes_close", referenced from:
      _zm_shutdown_sodium in libsodium.o
  "_sodium_add", referenced from:
      _zif_sodium_add in libsodium.o
     (maybe you meant: _zif_sodium_add)
  "_sodium_base642bin", referenced from:
      _zif_sodium_base642bin in libsodium.o
     (maybe you meant: _zif_sodium_base642bin)
  "_sodium_bin2base64", referenced from:
      _zif_sodium_bin2base64 in libsodium.o
     (maybe you meant: _zif_sodium_bin2base64)
  "_sodium_bin2hex", referenced from:
      _zif_sodium_bin2hex in libsodium.o
     (maybe you meant: _zif_sodium_bin2hex)
  "_sodium_compare", referenced from:
      _zif_sodium_compare in libsodium.o
     (maybe you meant: _zif_sodium_compare)
  "_sodium_hex2bin", referenced from:
      _zif_sodium_hex2bin in libsodium.o
     (maybe you meant: _zif_sodium_hex2bin)
  "_sodium_increment", referenced from:
      _zif_sodium_increment in libsodium.o
     (maybe you meant: _zif_sodium_increment)
  "_sodium_init", referenced from:
      _zm_startup_sodium in libsodium.o
  "_sodium_library_version_major", referenced from:
      _zm_startup_sodium in libsodium.o
  "_sodium_library_version_minor", referenced from:
      _zm_startup_sodium in libsodium.o
  "_sodium_memcmp", referenced from:
      _zif_sodium_memcmp in libsodium.o
     (maybe you meant: _zif_sodium_memcmp)
  "_sodium_memzero", referenced from:
      _zif_sodium_memzero in libsodium.o
      _zif_sodium_crypto_generichash_init in libsodium.o
      _zif_sodium_crypto_generichash_update in libsodium.o
      _zif_sodium_crypto_generichash_final in libsodium.o
      _zif_sodium_crypto_kx_client_session_keys in libsodium.o
      _zif_sodium_crypto_kx_server_session_keys in libsodium.o
     (maybe you meant: _zif_sodium_memzero)
  "_sodium_pad", referenced from:
      _zif_sodium_pad in libsodium.o
     (maybe you meant: _zif_sodium_pad)
  "_sodium_unpad", referenced from:
      _zif_sodium_unpad in libsodium.o
     (maybe you meant: _zif_sodium_unpad)
  "_sodium_version_string", referenced from:
      _zm_startup_sodium in libsodium.o
      _zm_info_sodium in libsodium.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

Ok, for :
---
"_php_addslashes", referenced from:
      _php_filter_add_slashes in sanitizing_filters.o
      _zif_addslashes in string.o
      _zif_stream_socket_client in streamsfuncs.o
     (maybe you meant: _php_addslashes_default, _php_addslashes_sse42 )
---

found in 'ext/standard/string.c' :

ZEND_ATTRIBUTE_UNUSED /* clang mistakenly warns about this */

Is there any way to make clang warns silently and don't trigger
en error or an option in ./configure ?

Hello, sorry for such late reply here. PHP bugs are now reported on GitHub issue tracker. I'm just adding a note here that this should be resolved on current macOS machines and PHP code also compiles fine.

In case this repeats somewhere else, please reopen the issue on GitHub.

And as a side quick-fix solution on the client-side installation what can be also done in such cases is adding the linker flag "-Wl,-undefined,dynamic_lookup":

    ./configure LDFLAGS=-Wl,-undefined,dynamic_lookup