Build Ruby 2.3 fails due to an openssl error

[Ana06]

I get an openssl error when trying to install Ruby 2.3.X. I have successfully installed 2.4.1, 2.5.5 and 2.6.2. It seems openssl 1.1 doesn't support Ruby < 2.3 but openssl 1.1 is required by ruby-build.

operative system: openSUSE Leap 15.1
openssl version: OpenSSL 1.1.0i-fips 14 Aug 2018
ruby-build version: 20190401
rbenv version: 1.1.1

It may be related to #850

Log rbenv install 2.3.3

compiling ossl_ssl.c
In file included from ossl.h:57:0,
                 from ossl_engine.c:10:
/usr/include/openssl/asn1_mac.h:10:2: error: #error "This file is obsolete; please update your software."
 #error "This file is obsolete; please update your software."
  ^~~~~
compiling ossl_pkey_rsa.c
In file included from ossl.h:57:0,
                 from ossl_x509.c:10:
/usr/include/openssl/asn1_mac.h:10:2: error: #error "This file is obsolete; please update your software."
 #error "This file is obsolete; please update your software."
  ^~~~~
In file included from ossl.h:57:0,
                 from ossl_cipher.c:10:
/usr/include/openssl/asn1_mac.h:10:2: error: #error "This file is obsolete; please update your software."
 #error "This file is obsolete; please update your software."
  ^~~~~
linking shared-object gdbm.so
In file included from ossl.h:57:0,
                 from ossl_pkcs12.c:5:
/usr/include/openssl/asn1_mac.h:10:2: error: #error "This file is obsolete; please update your software."
 #error "This file is obsolete; please update your software."
  ^~~~~
In file included from ossl.h:57:0,
                 from ossl_pkcs5.c:4:
/usr/include/openssl/asn1_mac.h:10:2: error: #error "This file is obsolete; please update your software."
 #error "This file is obsolete; please update your software."
  ^~~~~
In file included from ossl.h:57:0,
                 from ossl_x509attr.c:10:
/usr/include/openssl/asn1_mac.h:10:2: error: #error "This file is obsolete; please update your software."
 #error "This file is obsolete; please update your software."
  ^~~~~
In file included from ossl.h:222:0,
                 from ossl_engine.c:10:
openssl_missing.h:78:35: error: macro "EVP_MD_CTX_create" passed 1 arguments, but takes just 0
 EVP_MD_CTX *EVP_MD_CTX_create(void);
                                   ^
In file included from /usr/include/openssl/x509.h:23:0,
                 from /usr/include/openssl/x509v3.h:14,
                 from ossl.h:58,
                 from ossl_engine.c:10:
openssl_missing.h:82:6: error: expected declaration specifiers or ‘...’ before ‘(’ token
 void EVP_MD_CTX_init(EVP_MD_CTX *ctx);
      ^
openssl_missing.h:90:6: error: expected declaration specifiers or ‘...’ before ‘(’ token
 void EVP_MD_CTX_destroy(EVP_MD_CTX *ctx);
      ^
make[2]: *** [Makefile:301: ossl_engine.o] Error 1
make[2]: *** Waiting for unfinished jobs....
In file included from ossl.h:57:0,
                 from ossl_pkey_rsa.c:12:
/usr/include/openssl/asn1_mac.h:10:2: error: #error "This file is obsolete; please update your software."
 #error "This file is obsolete; please update your software."
  ^~~~~
In file included from ossl.h:57:0,
                 from ossl_ssl.c:12:
/usr/include/openssl/asn1_mac.h:10:2: error: #error "This file is obsolete; please update your software."
 #error "This file is obsolete; please update your software."
  ^~~~~
In file included from ossl.h:222:0,
                 from ossl_x509.c:10:
openssl_missing.h:78:35: error: macro "EVP_MD_CTX_create" passed 1 arguments, but takes just 0
 EVP_MD_CTX *EVP_MD_CTX_create(void);
                                   ^
In file included from /usr/include/openssl/x509.h:23:0,
                 from /usr/include/openssl/x509v3.h:14,
                 from ossl.h:58,
                 from ossl_x509.c:10:
openssl_missing.h:82:6: error: expected declaration specifiers or ‘...’ before ‘(’ token
 void EVP_MD_CTX_init(EVP_MD_CTX *ctx);
      ^
openssl_missing.h:90:6: error: expected declaration specifiers or ‘...’ before ‘(’ token
 void EVP_MD_CTX_destroy(EVP_MD_CTX *ctx);
      ^
make[2]: *** [Makefile:301: ossl_x509.o] Error 1
make[2]: Leaving directory '/tmp/ruby-build.20190721184856.920/ruby-2.3.3/ext/gdbm'
In file included from ossl.h:222:0,
                 from ossl_cipher.c:10:
openssl_missing.h:78:35: error: macro "EVP_MD_CTX_create" passed 1 arguments, but takes just 0
 EVP_MD_CTX *EVP_MD_CTX_create(void);
                                   ^
In file included from /usr/include/openssl/x509.h:23:0,
                 from /usr/include/openssl/x509v3.h:14,
                 from ossl.h:58,
                 from ossl_cipher.c:10:
openssl_missing.h:82:6: error: expected declaration specifiers or ‘...’ before ‘(’ token
 void EVP_MD_CTX_init(EVP_MD_CTX *ctx);
      ^
openssl_missing.h:90:6: error: expected declaration specifiers or ‘...’ before ‘(’ token
 void EVP_MD_CTX_destroy(EVP_MD_CTX *ctx);
      ^
In file included from ../.././include/ruby.h:33:0,
                 from ossl.h:30,
                 from ossl_cipher.c:10:
ossl_cipher.c: In function ‘ossl_cipher_new’:
ossl_cipher.c:17:37: error: invalid application of ‘sizeof’ to incomplete type ‘EVP_CIPHER_CTX {aka struct evp_cipher_ctx_st}’
     (DATA_PTR(obj) = (ctx) = ZALLOC(EVP_CIPHER_CTX))
                                     ^
../.././include/ruby/ruby.h:1603:61: note: in definition of macro ‘RB_ZALLOC_N’
 #define RB_ZALLOC_N(type,n) ((type*)ruby_xcalloc((n),sizeof(type)))
                                                             ^~~~
../.././include/ruby/ruby.h:1610:22: note: in expansion of macro ‘RB_ZALLOC’
 #define ZALLOC(type) RB_ZALLOC(type)
                      ^~~~~~~~~
ossl_cipher.c:17:30: note: in expansion of macro ‘ZALLOC’
     (DATA_PTR(obj) = (ctx) = ZALLOC(EVP_CIPHER_CTX))
                              ^~~~~~
ossl_cipher.c:69:5: note: in expansion of macro ‘AllocCipher’
     AllocCipher(ret, ctx);
     ^~~~~~~~~~~
ossl_cipher.c: In function ‘ossl_cipher_memsize’:
ossl_cipher.c:94:19: error: dereferencing pointer to incomplete type ‘EVP_CIPHER_CTX {aka const struct evp_cipher_ctx_st}’
     return sizeof(*ctx);
                   ^~~~
In file included from ../.././include/ruby.h:33:0,
                 from ossl.h:30,
                 from ossl_cipher.c:10:
ossl_cipher.c: In function ‘ossl_cipher_initialize’:
ossl_cipher.c:17:37: error: invalid application of ‘sizeof’ to incomplete type ‘EVP_CIPHER_CTX {aka struct evp_cipher_ctx_st}’
     (DATA_PTR(obj) = (ctx) = ZALLOC(EVP_CIPHER_CTX))
                                     ^
../.././include/ruby/ruby.h:1603:61: note: in definition of macro ‘RB_ZALLOC_N’
 #define RB_ZALLOC_N(type,n) ((type*)ruby_xcalloc((n),sizeof(type)))
                                                             ^~~~
../.././include/ruby/ruby.h:1610:22: note: in expansion of macro ‘RB_ZALLOC’
 #define ZALLOC(type) RB_ZALLOC(type)
                      ^~~~~~~~~
ossl_cipher.c:17:30: note: in expansion of macro ‘ZALLOC’
     (DATA_PTR(obj) = (ctx) = ZALLOC(EVP_CIPHER_CTX))
                              ^~~~~~
ossl_cipher.c:124:5: note: in expansion of macro ‘AllocCipher’
     AllocCipher(self, ctx);
     ^~~~~~~~~~~
ossl_cipher.c: In function ‘ossl_cipher_copy’:
ossl_cipher.c:17:37: error: invalid application of ‘sizeof’ to incomplete type ‘EVP_CIPHER_CTX {aka struct evp_cipher_ctx_st}’
     (DATA_PTR(obj) = (ctx) = ZALLOC(EVP_CIPHER_CTX))
                                     ^
../.././include/ruby/ruby.h:1603:61: note: in definition of macro ‘RB_ZALLOC_N’
 #define RB_ZALLOC_N(type,n) ((type*)ruby_xcalloc((n),sizeof(type)))
                                                             ^~~~
../.././include/ruby/ruby.h:1610:22: note: in expansion of macro ‘RB_ZALLOC’
 #define ZALLOC(type) RB_ZALLOC(type)
                      ^~~~~~~~~
ossl_cipher.c:17:30: note: in expansion of macro ‘ZALLOC’
     (DATA_PTR(obj) = (ctx) = ZALLOC(EVP_CIPHER_CTX))
                              ^~~~~~
ossl_cipher.c:152:2: note: in expansion of macro ‘AllocCipher’
  AllocCipher(self, ctx1);
  ^~~~~~~~~~~
make[2]: Entering directory '/tmp/ruby-build.20190721184856.920/ruby-2.3.3'
make[2]: warning: -jN forced in submake: disabling jobserver mode.
In file included from nkf.c:62:0:
nkf-utf8/nkf.c: In function ‘module_connection’:
nkf-utf8/nkf.c:5710:5: warning: this ‘if’ clause does not guard... [-Wmisleading-indentation]
     if (nkf_enc_unicode_p(output_encoding))
     ^~
nkf-utf8/nkf.c:5713:2: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the ‘if’
  if (x0201_f == NKF_UNSPECIFIED) {
  ^~
In file included from ossl.h:222:0,
                 from ossl_pkcs12.c:5:
openssl_missing.h:78:35: error: macro "EVP_MD_CTX_create" passed 1 arguments, but takes just 0
 EVP_MD_CTX *EVP_MD_CTX_create(void);
                                   ^
In file included from /usr/include/openssl/x509.h:23:0,
                 from /usr/include/openssl/x509v3.h:14,
                 from ossl.h:58,
                 from ossl_pkcs12.c:5:
openssl_missing.h:82:6: error: expected declaration specifiers or ‘...’ before ‘(’ token
 void EVP_MD_CTX_init(EVP_MD_CTX *ctx);
      ^
openssl_missing.h:90:6: error: expected declaration specifiers or ‘...’ before ‘(’ token
 void EVP_MD_CTX_destroy(EVP_MD_CTX *ctx);
      ^
ossl_cipher.c: In function ‘ossl_cipher_memsize’:
ossl_cipher.c:95:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^
make[2]: *** [Makefile:301: ossl_pkcs12.o] Error 1
compiling pathname.c
make[2]: *** [Makefile:301: ossl_cipher.o] Error 1
installing default pathname libraries
In file included from ossl.h:222:0,
                 from ossl_pkcs5.c:4:
openssl_missing.h:78:35: error: macro "EVP_MD_CTX_create" passed 1 arguments, but takes just 0
 EVP_MD_CTX *EVP_MD_CTX_create(void);
                                   ^
In file included from /usr/include/openssl/x509.h:23:0,
                 from /usr/include/openssl/x509v3.h:14,
                 from ossl.h:58,
                 from ossl_pkcs5.c:4:
openssl_missing.h:82:6: error: expected declaration specifiers or ‘...’ before ‘(’ token
 void EVP_MD_CTX_init(EVP_MD_CTX *ctx);
      ^
openssl_missing.h:90:6: error: expected declaration specifiers or ‘...’ before ‘(’ token
 void EVP_MD_CTX_destroy(EVP_MD_CTX *ctx);
      ^
make[2]: *** [Makefile:301: ossl_pkcs5.o] Error 1
nkf-utf8/nkf.c: In function ‘options’:
nkf-utf8/nkf.c:6807:22: warning: this statement may fall through [-Wimplicit-fallthrough=]
      fold_preserve_f = TRUE;
nkf-utf8/nkf.c:6808:2: note: here
  case 'f':   /* folding -f60 or -f */
  ^~~~
In file included from ossl.h:222:0,
                 from ossl_x509attr.c:10:
openssl_missing.h:78:35: error: macro "EVP_MD_CTX_create" passed 1 arguments, but takes just 0
 EVP_MD_CTX *EVP_MD_CTX_create(void);
                                   ^
In file included from /usr/include/openssl/x509.h:23:0,
                 from /usr/include/openssl/x509v3.h:14,
                 from ossl.h:58,
                 from ossl_x509attr.c:10:
openssl_missing.h:82:6: error: expected declaration specifiers or ‘...’ before ‘(’ token
 void EVP_MD_CTX_init(EVP_MD_CTX *ctx);
      ^
openssl_missing.h:90:6: error: expected declaration specifiers or ‘...’ before ‘(’ token
 void EVP_MD_CTX_destroy(EVP_MD_CTX *ctx);
      ^
ossl_x509attr.c: In function ‘ossl_x509attr_set_value’:
ossl_x509attr.c:206:12: error: dereferencing pointer to incomplete type ‘X509_ATTRIBUTE {aka struct x509_attributes_st}’
     if(attr->value.set){
            ^~
In file included from ossl.h:222:0,
                 from ossl_pkey_rsa.c:12:
openssl_missing.h:78:35: error: macro "EVP_MD_CTX_create" passed 1 arguments, but takes just 0
 EVP_MD_CTX *EVP_MD_CTX_create(void);
                                   ^
In file included from /usr/include/openssl/x509.h:23:0,
                 from /usr/include/openssl/x509v3.h:14,
                 from ossl.h:58,
                 from ossl_pkey_rsa.c:12:
openssl_missing.h:82:6: error: expected declaration specifiers or ‘...’ before ‘(’ token
 void EVP_MD_CTX_init(EVP_MD_CTX *ctx);
      ^
openssl_missing.h:90:6: error: expected declaration specifiers or ‘...’ before ‘(’ token
 void EVP_MD_CTX_destroy(EVP_MD_CTX *ctx);
      ^
ossl_pkey_rsa.c: In function ‘ossl_rsa_new’:
ossl_pkey_rsa.c:65:24: error: dereferencing pointer to incomplete type ‘EVP_PKEY {aka struct evp_pkey_st}’
  if (EVP_PKEY_type(pkey->type) != EVP_PKEY_RSA) {
                        ^~
ossl_pkey_rsa.c: In function ‘rsa_generate’:
ossl_pkey_rsa.c:103:14: error: storage size of ‘cb’ isn’t known
     BN_GENCB cb;
              ^~
ossl_pkey_rsa.c:103:14: warning: unused variable ‘cb’ [-Wunused-variable]
ossl_pkey_rsa.c: In function ‘ossl_rsa_is_private’:
ossl_pkey_rsa.c:291:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^
make[2]: *** [Makefile:301: ossl_pkey_rsa.o] Error 1
In file included from ossl.h:222:0,
                 from ossl_ssl.c:12:
openssl_missing.h:78:35: error: macro "EVP_MD_CTX_create" passed 1 arguments, but takes just 0
 EVP_MD_CTX *EVP_MD_CTX_create(void);
                                   ^
In file included from /usr/include/openssl/x509.h:23:0,
                 from /usr/include/openssl/x509v3.h:14,
                 from ossl.h:58,
                 from ossl_ssl.c:12:
openssl_missing.h:82:6: error: expected declaration specifiers or ‘...’ before ‘(’ token
 void EVP_MD_CTX_init(EVP_MD_CTX *ctx);
      ^
openssl_missing.h:90:6: error: expected declaration specifiers or ‘...’ before ‘(’ token
 void EVP_MD_CTX_destroy(EVP_MD_CTX *ctx);
      ^
ossl_ssl.c:90:5: warning: ‘TLSv1_method’ is deprecated [-Wdeprecated-declarations]
     OSSL_SSL_METHOD_ENTRY(TLSv1),
     ^~~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/openssl/e_os2.h:13:0,
                 from /usr/include/openssl/err.h:13,
                 from ossl.h:56,
                 from ossl_ssl.c:12:
/usr/include/openssl/ssl.h:1632:1: note: declared here
 DEPRECATEDIN_1_1_0(__owur const SSL_METHOD *TLSv1_method(void)) /* TLSv1.0 */
 ^
ossl_ssl.c:91:5: warning: ‘TLSv1_server_method’ is deprecated [-Wdeprecated-declarations]
     OSSL_SSL_METHOD_ENTRY(TLSv1_server),
     ^~~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/openssl/e_os2.h:13:0,
                 from /usr/include/openssl/err.h:13,
                 from ossl.h:56,
                 from ossl_ssl.c:12:
/usr/include/openssl/ssl.h:1633:1: note: declared here
 DEPRECATEDIN_1_1_0(__owur const SSL_METHOD *TLSv1_server_method(void)) /* TLSv1.0 */
 ^
ossl_ssl.c:92:5: warning: ‘TLSv1_client_method’ is deprecated [-Wdeprecated-declarations]
     OSSL_SSL_METHOD_ENTRY(TLSv1_client),
     ^~~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/openssl/e_os2.h:13:0,
                 from /usr/include/openssl/err.h:13,
                 from ossl.h:56,
                 from ossl_ssl.c:12:
/usr/include/openssl/ssl.h:1634:1: note: declared here
 DEPRECATEDIN_1_1_0(__owur const SSL_METHOD *TLSv1_client_method(void)) /* TLSv1.0 */
 ^
ossl_ssl.c:95:5: warning: ‘TLSv1_2_method’ is deprecated [-Wdeprecated-declarations]
     OSSL_SSL_METHOD_ENTRY(TLSv1_2),
     ^~~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/openssl/e_os2.h:13:0,
                 from /usr/include/openssl/err.h:13,
                 from ossl.h:56,
                 from ossl_ssl.c:12:
/usr/include/openssl/ssl.h:1644:1: note: declared here
 DEPRECATEDIN_1_1_0(__owur const SSL_METHOD *TLSv1_2_method(void)) /* TLSv1.2 */
 ^
ossl_ssl.c:96:5: warning: ‘TLSv1_2_server_method’ is deprecated [-Wdeprecated-declarations]
     OSSL_SSL_METHOD_ENTRY(TLSv1_2_server),
     ^~~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/openssl/e_os2.h:13:0,
                 from /usr/include/openssl/err.h:13,
                 from ossl.h:56,
                 from ossl_ssl.c:12:
/usr/include/openssl/ssl.h:1645:1: note: declared here
 DEPRECATEDIN_1_1_0(__owur const SSL_METHOD *TLSv1_2_server_method(void)) /* TLSv1.2 */
 ^
ossl_ssl.c:97:5: warning: ‘TLSv1_2_client_method’ is deprecated [-Wdeprecated-declarations]
     OSSL_SSL_METHOD_ENTRY(TLSv1_2_client),
     ^~~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/openssl/e_os2.h:13:0,
                 from /usr/include/openssl/err.h:13,
                 from ossl.h:56,
                 from ossl_ssl.c:12:
/usr/include/openssl/ssl.h:1646:1: note: declared here
 DEPRECATEDIN_1_1_0(__owur const SSL_METHOD *TLSv1_2_client_method(void)) /* TLSv1.2 */
 ^
ossl_ssl.c:101:5: warning: ‘TLSv1_1_method’ is deprecated [-Wdeprecated-declarations]
     OSSL_SSL_METHOD_ENTRY(TLSv1_1),
     ^~~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/openssl/e_os2.h:13:0,
                 from /usr/include/openssl/err.h:13,
                 from ossl.h:56,
                 from ossl_ssl.c:12:
/usr/include/openssl/ssl.h:1638:1: note: declared here
 DEPRECATEDIN_1_1_0(__owur const SSL_METHOD *TLSv1_1_method(void)) /* TLSv1.1 */
 ^
ossl_ssl.c:102:5: warning: ‘TLSv1_1_server_method’ is deprecated [-Wdeprecated-declarations]
     OSSL_SSL_METHOD_ENTRY(TLSv1_1_server),
     ^~~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/openssl/e_os2.h:13:0,
                 from /usr/include/openssl/err.h:13,
                 from ossl.h:56,
                 from ossl_ssl.c:12:
/usr/include/openssl/ssl.h:1639:1: note: declared here
 DEPRECATEDIN_1_1_0(__owur const SSL_METHOD *TLSv1_1_server_method(void)) /* TLSv1.1 */
 ^
ossl_ssl.c:103:5: warning: ‘TLSv1_1_client_method’ is deprecated [-Wdeprecated-declarations]
     OSSL_SSL_METHOD_ENTRY(TLSv1_1_client),
     ^~~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/openssl/e_os2.h:13:0,
                 from /usr/include/openssl/err.h:13,
                 from ossl.h:56,
                 from ossl_ssl.c:12:
/usr/include/openssl/ssl.h:1640:1: note: declared here
 DEPRECATEDIN_1_1_0(__owur const SSL_METHOD *TLSv1_1_client_method(void)) /* TLSv1.1 */
 ^
ossl_ssl.c: In function ‘ossl_sslctx_free’:
ossl_ssl.c:132:5: error: dereferencing pointer to incomplete type ‘SSL_CTX {aka struct ssl_ctx_st}’
  ctx->cert_store = NULL;
     ^~
In file included from nkf.c:62:0:
nkf-utf8/nkf.c: In function ‘set_input_encoding’:
nkf-utf8/nkf.c:1238:5: warning: this statement may fall through [-Wimplicit-fallthrough=]
  if (x0201_f == NKF_UNSPECIFIED) x0201_f = FALSE; /* -x specified implicitly */
     ^
nkf-utf8/nkf.c:1239:5: note: here
     case CP50220:
     ^~~~
ossl_x509attr.c: In function ‘ossl_x509attr_get_value’:
ossl_x509attr.c:238:11: warning: implicit declaration of function ‘i2d_ASN1_SET_OF_ASN1_TYPE’; did you mean ‘i2d_ASN1_SET_ANY’? [-Wimplicit-function-declaration]
  length = i2d_ASN1_SET_OF_ASN1_TYPE(attr->value.set,
           ^~~~~~~~~~~~~~~~~~~~~~~~~
           i2d_ASN1_SET_ANY
ossl_ssl.c: In function ‘ossl_call_tmp_dh_callback’:
ossl_ssl.c:246:27: error: dereferencing pointer to incomplete type ‘EVP_PKEY {aka struct evp_pkey_st}’
     if (EVP_PKEY_type(pkey->type) != EVP_PKEY_DH) return Qfalse;
                           ^~
ossl_ssl.c: In function ‘ossl_sslctx_session_new_cb’:
ossl_ssl.c:387:5: warning: implicit declaration of function ‘CRYPTO_add’; did you mean ‘CRYPTO_free’? [-Wimplicit-function-declaration]
     CRYPTO_add(&sess->references, 1, CRYPTO_LOCK_SSL_SESSION);
     ^~~~~~~~~~
     CRYPTO_free
ossl_ssl.c:387:21: error: dereferencing pointer to incomplete type ‘SSL_SESSION {aka struct ssl_session_st}’
     CRYPTO_add(&sess->references, 1, CRYPTO_LOCK_SSL_SESSION);
                     ^~
make[2]: *** [Makefile:301: ossl_x509attr.o] Error 1
ossl_ssl.c:387:38: error: ‘CRYPTO_LOCK_SSL_SESSION’ undeclared (first use in this function); did you mean ‘CRYPTO_EX_INDEX_SSL_SESSION’?
     CRYPTO_add(&sess->references, 1, CRYPTO_LOCK_SSL_SESSION);
                                      ^~~~~~~~~~~~~~~~~~~~~~~
                                      CRYPTO_EX_INDEX_SSL_SESSION
ossl_ssl.c:387:38: note: each undeclared identifier is reported only once for each function it appears in
ossl_ssl.c: In function ‘ossl_sslctx_session_remove_cb’:
ossl_ssl.c:436:38: error: ‘CRYPTO_LOCK_SSL_SESSION’ undeclared (first use in this function); did you mean ‘CRYPTO_EX_INDEX_SSL_SESSION’?
     CRYPTO_add(&sess->references, 1, CRYPTO_LOCK_SSL_SESSION);
                                      ^~~~~~~~~~~~~~~~~~~~~~~
                                      CRYPTO_EX_INDEX_SSL_SESSION
ossl_ssl.c: In function ‘ssl_info_cb’:
ossl_ssl.c:644:17: warning: implicit declaration of function ‘SSL_state’; did you mean ‘SSL_write’? [-Wimplicit-function-declaration]
     int state = SSL_state(ssl);
                 ^~~~~~~~~
                 SSL_write
ossl_ssl.c: In function ‘ossl_sslctx_setup’:
ossl_ssl.c:715:2: warning: implicit declaration of function ‘SSL_CTX_set_tmp_ecdh_callback’; did you mean ‘SSL_CTX_set_tmp_dh_callback’? [-Wimplicit-function-declaration]
  SSL_CTX_set_tmp_ecdh_callback(ctx, ossl_tmp_ecdh_callback);
  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  SSL_CTX_set_tmp_dh_callback
ossl_ssl.c:835:31: warning: passing argument 2 of ‘SSL_CTX_sess_set_get_cb’ from incompatible pointer type [-Wincompatible-pointer-types]
  SSL_CTX_sess_set_get_cb(ctx, ossl_sslctx_session_get_cb);
                               ^~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from ossl.h:59:0,
                 from ossl_ssl.c:12:
/usr/include/openssl/ssl.h:647:6: note: expected ‘SSL_SESSION * (*)(struct ssl_st *, const unsigned char *, int,  int *) {aka struct ssl_session_st * (*)(struct ssl_st *, const unsigned char *, int,  int *)}’ but argument is of type ‘SSL_SESSION * (*)(SSL *, unsigned char *, int,  int *) {aka struct ssl_session_st * (*)(struct ssl_st *, unsigned char *, int,  int *)}’
 void SSL_CTX_sess_set_get_cb(SSL_CTX *ctx,
      ^~~~~~~~~~~~~~~~~~~~~~~
ossl_ssl.c: In function ‘ossl_sslctx_get_ciphers’:
ossl_ssl.c:902:16: warning: assignment discards ‘const’ qualifier from pointer target type [-Wdiscarded-qualifiers]
         cipher = sk_SSL_CIPHER_value(ciphers, i);
                ^
ossl_ssl.c: In function ‘ossl_ssl_write_internal’:
ossl_ssl.c:1557:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
   if (errno) rb_sys_fail(0);
      ^
ossl_ssl.c:1558:6: note: here
      default:
      ^~~~~~~
ossl_ssl.c: In function ‘ossl_tmp_ecdh_callback’:
ossl_ssl.c:299:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^
ossl_ssl.c: In function ‘ossl_tmp_dh_callback’:
ossl_ssl.c:265:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^
make[2]: *** [Makefile:301: ossl_ssl.o] Error 1
make[2]: Leaving directory '/tmp/ruby-build.20190721184856.920/ruby-2.3.3/ext/openssl'
make[1]: *** [exts.mk:209: ext/openssl/all] Error 2
make[1]: *** Waiting for unfinished jobs....
linking shared-object json/ext/parser.so
make[2]: Leaving directory '/tmp/ruby-build.20190721184856.920/ruby-2.3.3/ext/json/parser'
linking shared-object objspace.so
linking shared-object json/ext/generator.so
make[2]: Leaving directory '/tmp/ruby-build.20190721184856.920/ruby-2.3.3/ext/objspace'
make[2]: Leaving directory '/tmp/ruby-build.20190721184856.920/ruby-2.3.3/ext/json/generator'
linking shared-object pathname.so
make[2]: Leaving directory '/tmp/ruby-build.20190721184856.920/ruby-2.3.3/ext/pathname'
linking shared-object bigdecimal.so
make[2]: Leaving directory '/tmp/ruby-build.20190721184856.920/ruby-2.3.3/ext/bigdecimal'
linking shared-object date_core.so
make[2]: Leaving directory '/tmp/ruby-build.20190721184856.920/ruby-2.3.3/ext/date'
linking shared-object nkf.so
make[2]: Leaving directory '/tmp/ruby-build.20190721184856.920/ruby-2.3.3/ext/nkf'
make[1]: Leaving directory '/tmp/ruby-build.20190721184856.920/ruby-2.3.3'
make: *** [uncommon.mk:203: build-ext] Error 2

[hsbt]

Ruby 2.3 didn't support OpenSSL 1.1.x. and it's already EOL status.

openssl 1.1 is required by ruby-build.

I'm not sure what means this. The definition of ruby-build for Ruby 2.3 uses openssl-1.0.x: https://github.com/rbenv/ruby-build/blob/master/share/ruby-build/2.3.8#L1

[Ana06]

The ruby-build openSUSE package requires libopenssl-devel 1.1 (which requires libopenssl 1.0) , which I assume makes that ruby-build fails to install openssl 1.0 and consequently the installation of Ruby 2.3 fails.

I have removed this requirement in the openSUSE ruby-build package and installed libopenssl-devel 1.0 (which requires libopenssl 1.0) and this new version of ruby-build. In this way I can install Ruby 2.3 and previous Ruby versions.

I am not sure if there is a nice way to fix this problem apart of what I did (which is not really nice and uses a modified package). I know Ruby 2.3 is already in EOL status, but it is still used in many places, such as programming challenges like Google Code Jam and Hacker Earth (for those kind of things I find ruby-build + rbenv really useful).