According to the php manual I should be able to use the CURLOPT_PROXYHEADER constant:
CURLOPT_PROXYHEADER (integer)
Available since PHP 7.0.7 and cURL7.37.0
But I get this error:
Notice: Use of undefined constant CURLOPT_PROXYHEADER - assumed 'CURLOPT_PROXYHEADER'
My php version is:
php -v
PHP 7.1.0RC6 (cli) ( NTS )
I have php7.1-curl insalled.
My curl version is:
curl --version
curl 7.51.0 (x86_64-pc-linux-gnu) libcurl/7.51.0 OpenSSL/1.0.1f zlib/1.2.8
Why can't I use the constant?
Edit: Added curl part of phpinfo:
curl
cURL support => enabled
cURL Information => 7.51.0
Age => 3
Features
AsynchDNS => No
CharConv => No
Debug => No
GSS-Negotiate => No
IDN => No
IPv6 => Yes
krb4 => No
Largefile => Yes
libz => Yes
NTLM => Yes
NTLMWB => Yes
SPNEGO => No
SSL => Yes
SSPI => No
TLS-SRP => Yes
HTTP2 => No
Protocols => dict, file, ftp, ftps, gopher, http, https, imap, imaps, pop3, pop3s, rtsp, smb, smbs, smtp, smtps, telnet, tftp
Host => x86_64-pc-linux-gnu
SSL Version => OpenSSL/1.0.1f
ZLib Version => 1.2.8