Error installing puma: ERROR: Failed to build gem native extension

[klueless-io]

Describe the bug
I have tried to do a gem install puma and get an error.

I have a brand new Mac that I am setting up

I have worked out that any version <= 4.2.1 works fine on my computer
I am using asdf version manager

Works: gem install puma -v '4.2.1'
Fails: gem install puma -v '4.3.0' or `gem install puma'

Error

I have tried each of these commands to get this to work

gem install puma
gem install puma -v '4.3.0' -- --with-ldflags=-L/usr/local/opt/openssl@1.1/lib --with-cppflags=-I/usr/local/opt/openssl@1.1/include

Building native extensions. This could take a while...
ERROR:  Error installing puma:
	ERROR: Failed to build gem native extension.

    current directory: /Users/myname/.asdf/installs/ruby/2.7.1/lib/ruby/gems/2.7.0/gems/puma-4.3.5/ext/puma_http11
/Users/myname/.asdf/installs/ruby/2.7.1/bin/ruby -I /Users/myname/.asdf/installs/ruby/2.7.1/lib/ruby/site_ruby/2.7.0 -r ./siteconf20200806-17963-1cqtelz.rb extconf.rb
checking for BIO_read() in -lcrypto... yes
checking for SSL_CTX_new() in -lssl... yes
checking for openssl/bio.h... yes
checking for DTLS_method() in openssl/ssl.h... yes
checking for TLS_server_method() in openssl/ssl.h... yes
checking for SSL_CTX_set_min_proto_version in openssl/ssl.h... yes
creating Makefile

current directory: /Users/myname/.asdf/installs/ruby/2.7.1/lib/ruby/gems/2.7.0/gems/puma-4.3.5/ext/puma_http11
make "DESTDIR=" clean

current directory: /Users/myname/.asdf/installs/ruby/2.7.1/lib/ruby/gems/2.7.0/gems/puma-4.3.5/ext/puma_http11
make "DESTDIR="
compiling http11_parser.c
ext/puma_http11/http11_parser.c:44:18: warning: unused variable 'puma_parser_en_main' [-Wunused-const-variable]
static const int puma_parser_en_main = 1;
                 ^
1 warning generated.
compiling io_buffer.c
compiling mini_ssl.c
mini_ssl.c:145:7: warning: unused variable 'min' [-Wunused-variable]
  int min, ssl_options;
      ^
mini_ssl.c:299:40: warning: function 'raise_error' could be declared with attribute 'noreturn' [-Wmissing-noreturn]
void raise_error(SSL* ssl, int result) {
                                       ^
2 warnings generated.
compiling puma_http11.c
puma_http11.c:203:22: error: implicitly declaring library function 'isspace' with type 'int (int)' [-Werror,-Wimplicit-function-declaration]
  while (vlen > 0 && isspace(value[vlen - 1])) vlen--;
                     ^
puma_http11.c:203:22: note: include the header <ctype.h> or explicitly provide a declaration for 'isspace'
1 error generated.
make: *** [puma_http11.o] Error 1

make failed, exit code 2

Gem files will remain installed in /Users/myname/.asdf/installs/ruby/2.7.1/lib/ruby/gems/2.7.0/gems/puma-4.3.5 for inspection.
Results logged to /Users/myname/.asdf/installs/ruby/2.7.1/lib/ruby/gems/2.7.0/extensions/x86_64-darwin-19/2.7.0/puma-4.3.5/gem_make.out

I saw on this thread that you need OpenSSL 1.1

OpenSSL@1.1

I reinstalled openssl

brew reinstall openssl@1.1

==> Downloading https://homebrew.bintray.com/bottles/openssl%401.1-1.1.1g.catalina.bottle.tar.gz
Already downloaded: /Users/myname/Library/Caches/Homebrew/downloads/d6b7a6d80c588c89e79f350ce3e05c95d31d804291cc120efcbb6c9478607a41--openssl@1.1-1.1.1g.catalina.bottle.tar.gz
==> Reinstalling openssl@1.1
==> Pouring openssl@1.1-1.1.1g.catalina.bottle.tar.gz
==> Caveats
A CA file has been bootstrapped using certificates from the system
keychain. To add additional certificates, place .pem files in
  /usr/local/etc/openssl@1.1/certs

and run
  /usr/local/opt/openssl@1.1/bin/c_rehash

openssl@1.1 is keg-only, which means it was not symlinked into /usr/local,
because macOS provides LibreSSL.

If you need to have openssl@1.1 first in your PATH run:
  echo 'export PATH="/usr/local/opt/openssl@1.1/bin:$PATH"' >> ~/.zshrc

For compilers to find openssl@1.1 you may need to set:
  export LDFLAGS="-L/usr/local/opt/openssl@1.1/lib"
  export CPPFLAGS="-I/usr/local/opt/openssl@1.1/include"

For pkg-config to find openssl@1.1 you may need to set:
  export PKG_CONFIG_PATH="/usr/local/opt/openssl@1.1/lib/pkgconfig"

I tested with these lines in .zshrc

export PATH="/usr/local/opt/openssl@1.1/bin:$PATH"
export LDFLAGS="-L/usr/local/opt/openssl@1.1/lib"
export CPPFLAGS="-I/usr/local/opt/openssl@1.1/include"
export PKG_CONFIG_PATH="/usr/local/opt/openssl@1.1/lib/pkgconfig"

[dentarg]

@klueless-io see comments #2304 (comment) and #2304 (comment) for a workaround

[klueless-io]

Thankyou @dentarg

[MSP-Greg]

Fixed in 4.x branch via #2314

[deepakmahakale]

This works for puma ~> 6.0

PUMA_DISABLE_SSL=1 gem install puma -v "6.2.1"