Compilation error when using PlatformIO

[MicSG-dev]

When using PlatformIO with the following platformio.ini file:

[env:esp32dev]
platform = espressif32
board = esp32dev
framework = arduino
lib_deps =
    https://github.com/sstaub/Ethernet3.git

And running the WebServer example, several compilation errors occur:

src/main.cpp: In function 'void loop()':
src/main.cpp:52:43: error: cannot allocate an object of abstract type 'EthernetClient'
   52 |   EthernetClient client = server.available();
      |                           ~~~~~~~~~~~~~~~~^~
In file included from .pio/libdeps/esp32dev/Ethernet3/src/Ethernet3.h:16,
                 from src/main.cpp:20:
.pio/libdeps/esp32dev/Ethernet3/src/EthernetClient.h:8:7: note:   because the following virtual functions are pure within 'EthernetClient':
    8 | class EthernetClient : public Client {
      |       ^~~~~~~~~~~~~~
In file included from C:/Users/MichelGalvao/.platformio/packages/framework-arduinoespressif32@src-e5a7fd5d9117bd8a322277fde59ac3d3/cores/esp32/Arduino.h:197,
                 from src/main.cpp:18:
C:/Users/MichelGalvao/.platformio/packages/framework-arduinoespressif32@src-e5a7fd5d9117bd8a322277fde59ac3d3/cores/esp32/Client.h:29:15: note:     'virtual int Client::connect(IPAddress, uint16_t, int32_t)'
   29 |   virtual int connect(IPAddress ip, uint16_t port, int32_t timeout) = 0;
      |               ^~~~~~~
C:/Users/MichelGalvao/.platformio/packages/framework-arduinoespressif32@src-e5a7fd5d9117bd8a322277fde59ac3d3/cores/esp32/Client.h:31:15: note:     'virtual int Client::connect(const char*, uint16_t, int32_t)'
   31 |   virtual int connect(const char *host, uint16_t port, int32_t timeout) = 0;
      |               ^~~~~~~
src/main.cpp:52:18: error: cannot declare variable 'client' to be of abstract type 'EthernetClient'
   52 |   EthernetClient client = server.available();
      |                  ^~~~~~
Compiling .pio\build\esp32dev\FrameworkArduino\FunctionalInterrupt.cpp.o
*** [.pio\build\esp32dev\src\main.cpp.o] Error 1
In file included from .pio/libdeps/esp32dev/Ethernet3/src/Dns.cpp:7:
.pio/libdeps/esp32dev/Ethernet3/src/utility/util.h:4: warning: "htons" redefined
    4 | #define htons(x) ( ((x)<< 8 & 0xFF00) | \
      |
In file included from C:/Users/MichelGalvao/.platformio/packages/framework-arduinoespressif32-libs/esp32/include/lwip/lwip/src/include/lwip/arch.h:48,
                 from C:/Users/MichelGalvao/.platformio/packages/framework-arduinoespressif32-libs/esp32/include/lwip/lwip/src/include/lwip/debug.h:40,
                 from C:/Users/MichelGalvao/.platformio/packages/framework-arduinoespressif32-libs/esp32/include/lwip/lwip/src/include/lwip/opt.h:52,
                 from C:/Users/MichelGalvao/.platformio/packages/framework-arduinoespressif32-libs/esp32/include/lwip/lwip/src/include/lwip/ip_addr.h:40,
                 from C:/Users/MichelGalvao/.platformio/packages/framework-arduinoespressif32@src-e5a7fd5d9117bd8a322277fde59ac3d3/cores/esp32/IPAddress.h:25,
                 from C:/Users/MichelGalvao/.platformio/packages/framework-arduinoespressif32@src-e5a7fd5d9117bd8a322277fde59ac3d3/cores/esp32/Arduino.h:196,
                 from .pio/libdeps/esp32dev/Ethernet3/src/utility/w5500.h:20,
                 from .pio/libdeps/esp32dev/Ethernet3/src/Dns.cpp:5:
C:/Users/MichelGalvao/.platformio/packages/framework-arduinoespressif32-libs/esp32/include/lwip/port/esp32xx/include/arch/cc.h:28: note: this is the location of the previous definition
   28 | #define htons(x) __builtin_bswap16(x)
      |
.pio/libdeps/esp32dev/Ethernet3/src/utility/util.h:6: warning: "ntohs" redefined
    6 | #define ntohs(x) htons(x)
      |
C:/Users/MichelGalvao/.platformio/packages/framework-arduinoespressif32-libs/esp32/include/lwip/port/esp32xx/include/arch/cc.h:29: note: this is the location of the previous definition
   29 | #define ntohs(x) __builtin_bswap16(x)
      |
.pio/libdeps/esp32dev/Ethernet3/src/utility/util.h:8: warning: "htonl" redefined
    8 | #define htonl(x) ( ((x)<<24 & 0xFF000000UL) | \
      |
C:/Users/MichelGalvao/.platformio/packages/framework-arduinoespressif32-libs/esp32/include/lwip/port/esp32xx/include/arch/cc.h:30: note: this is the location of the previous definition
   30 | #define htonl(x) __builtin_bswap32(x)
      |
.pio/libdeps/esp32dev/Ethernet3/src/utility/util.h:12: warning: "ntohl" redefined
   12 | #define ntohl(x) htonl(x)
      |
C:/Users/MichelGalvao/.platformio/packages/framework-arduinoespressif32-libs/esp32/include/lwip/port/esp32xx/include/arch/cc.h:31: note: this is the location of the previous definition
   31 | #define ntohl(x) __builtin_bswap32(x)
      |
In file included from .pio/libdeps/esp32dev/Ethernet3/src/Dhcp.cpp:10:
.pio/libdeps/esp32dev/Ethernet3/src/utility/util.h:4: warning: "htons" redefined
    4 | #define htons(x) ( ((x)<< 8 & 0xFF00) | \
      |
In file included from C:/Users/MichelGalvao/.platformio/packages/framework-arduinoespressif32-libs/esp32/include/lwip/lwip/src/include/lwip/arch.h:48,
                 from C:/Users/MichelGalvao/.platformio/packages/framework-arduinoespressif32-libs/esp32/include/lwip/lwip/src/include/lwip/debug.h:40,
                 from C:/Users/MichelGalvao/.platformio/packages/framework-arduinoespressif32-libs/esp32/include/lwip/lwip/src/include/lwip/opt.h:52,
                 from C:/Users/MichelGalvao/.platformio/packages/framework-arduinoespressif32-libs/esp32/include/lwip/lwip/src/include/lwip/ip_addr.h:40,
                 from C:/Users/MichelGalvao/.platformio/packages/framework-arduinoespressif32@src-e5a7fd5d9117bd8a322277fde59ac3d3/cores/esp32/IPAddress.h:25,
                 from C:/Users/MichelGalvao/.platformio/packages/framework-arduinoespressif32@src-e5a7fd5d9117bd8a322277fde59ac3d3/cores/esp32/Arduino.h:196,
                 from .pio/libdeps/esp32dev/Ethernet3/src/utility/w5500.h:20,
                 from .pio/libdeps/esp32dev/Ethernet3/src/Dhcp.cpp:4:
C:/Users/MichelGalvao/.platformio/packages/framework-arduinoespressif32-libs/esp32/include/lwip/port/esp32xx/include/arch/cc.h:28: note: this is the location of the previous definition
   28 | #define htons(x) __builtin_bswap16(x)
      |
.pio/libdeps/esp32dev/Ethernet3/src/utility/util.h:6: warning: "ntohs" redefined
    6 | #define ntohs(x) htons(x)
      |
C:/Users/MichelGalvao/.platformio/packages/framework-arduinoespressif32-libs/esp32/include/lwip/port/esp32xx/include/arch/cc.h:29: note: this is the location of the previous definition
   29 | #define ntohs(x) __builtin_bswap16(x)
      |
.pio/libdeps/esp32dev/Ethernet3/src/utility/util.h:8: warning: "htonl" redefined
    8 | #define htonl(x) ( ((x)<<24 & 0xFF000000UL) | \
      |
C:/Users/MichelGalvao/.platformio/packages/framework-arduinoespressif32-libs/esp32/include/lwip/port/esp32xx/include/arch/cc.h:30: note: this is the location of the previous definition
   30 | #define htonl(x) __builtin_bswap32(x)
      |
.pio/libdeps/esp32dev/Ethernet3/src/utility/util.h:12: warning: "ntohl" redefined
   12 | #define ntohl(x) htonl(x)
      |
C:/Users/MichelGalvao/.platformio/packages/framework-arduinoespressif32-libs/esp32/include/lwip/port/esp32xx/include/arch/cc.h:31: note: this is the location of the previous definition
   31 | #define ntohl(x) __builtin_bswap32(x)
      |
.pio/libdeps/esp32dev/Ethernet3/src/EthernetServer.cpp: In member function 'virtual void EthernetServer::begin()':
.pio/libdeps/esp32dev/Ethernet3/src/EthernetServer.cpp:19:20: error: cannot declare variable 'client' to be of abstract type 'EthernetClient'
   19 |     EthernetClient client(sock);
      |                    ^~~~~~
In file included from .pio/libdeps/esp32dev/Ethernet3/src/Ethernet3.h:16,
                 from .pio/libdeps/esp32dev/Ethernet3/src/EthernetServer.cpp:7:
.pio/libdeps/esp32dev/Ethernet3/src/EthernetClient.h:8:7: note:   because the following virtual functions are pure within 'EthernetClient':
    8 | class EthernetClient : public Client {
      |       ^~~~~~~~~~~~~~
In file included from C:/Users/MichelGalvao/.platformio/packages/framework-arduinoespressif32@src-e5a7fd5d9117bd8a322277fde59ac3d3/cores/esp32/Arduino.h:197,
                 from .pio/libdeps/esp32dev/Ethernet3/src/utility/w5500.h:20,
                 from .pio/libdeps/esp32dev/Ethernet3/src/EthernetServer.cpp:1:
C:/Users/MichelGalvao/.platformio/packages/framework-arduinoespressif32@src-e5a7fd5d9117bd8a322277fde59ac3d3/cores/esp32/Client.h:29:15: note:     'virtual int Client::connect(IPAddress, uint16_t, int32_t)'
   29 |   virtual int connect(IPAddress ip, uint16_t port, int32_t timeout) = 0;
      |               ^~~~~~~
C:/Users/MichelGalvao/.platformio/packages/framework-arduinoespressif32@src-e5a7fd5d9117bd8a322277fde59ac3d3/cores/esp32/Client.h:31:15: note:     'virtual int Client::connect(const char*, uint16_t, int32_t)'
   31 |   virtual int connect(const char *host, uint16_t port, int32_t timeout) = 0;
      |               ^~~~~~~
.pio/libdeps/esp32dev/Ethernet3/src/EthernetServer.cpp: In member function 'void EthernetServer::accept()':
.pio/libdeps/esp32dev/Ethernet3/src/EthernetServer.cpp:34:20: error: cannot declare variable 'client' to be of abstract type 'EthernetClient'
   34 |     EthernetClient client(sock);
      |                    ^~~~~~
.pio/libdeps/esp32dev/Ethernet3/src/EthernetServer.cpp: At global scope:
.pio/libdeps/esp32dev/Ethernet3/src/EthernetServer.cpp:51:16: error: invalid abstract return type for member function 'EthernetClient EthernetServer::available()'
   51 | EthernetClient EthernetServer::available()
      |                ^~~~~~~~~~~~~~
.pio/libdeps/esp32dev/Ethernet3/src/EthernetServer.cpp: In member function 'EthernetClient EthernetServer::available()':
.pio/libdeps/esp32dev/Ethernet3/src/EthernetServer.cpp:56:20: error: cannot declare variable 'client' to be of abstract type 'EthernetClient'
   56 |     EthernetClient client(sock);
      |                    ^~~~~~
.pio/libdeps/esp32dev/Ethernet3/src/EthernetServer.cpp:62:16: error: cannot allocate an object of abstract type 'EthernetClient'
   62 |         return client;
      |                ^~~~~~
.pio/libdeps/esp32dev/Ethernet3/src/EthernetServer.cpp:67:37: error: invalid cast to abstract class type 'EthernetClient'
   67 |   return EthernetClient(MAX_SOCK_NUM);
      |                                     ^
.pio/libdeps/esp32dev/Ethernet3/src/EthernetServer.cpp: In member function 'virtual size_t EthernetServer::write(const uint8_t*, size_t)':
.pio/libdeps/esp32dev/Ethernet3/src/EthernetServer.cpp:82:20: error: cannot declare variable 'client' to be of abstract type 'EthernetClient'
   82 |     EthernetClient client(sock);
      |                    ^~~~~~
*** [.pio\build\esp32dev\lib654\Ethernet3\EthernetServer.cpp.o] Error 1