I think there is no straight way to pass a longer timeout to the Net::Telnet instance. As a workaround, you can reach deep into the nested objects:

$mech->repl->repl->timeout(100000);
[download]

But I wonder - WWW::Mechanize::Firefox polls for results from Firefox, so there should be no timeout even if a website is slow to respond. The main cause I know for getting timeout errors is when I send invalid Javascript code over to Firefox.

$mech->repl->repl->timeout(100000);
[download]

Unfortunatly it does not work:
Can't locate object method "timeout" via package "MozRepl"

Documentation says this should:

$mech->repl->repl->setup_client( { extra_client_args => { timeout => 1
+80 } } );
[download]


But after this statement $mech->get() raises an error:
MozRepl::RemoteObject: TypeError: repl.breakLink is not a function


But I wonder - WWW::Mechanize::Firefox polls for results from Firefox, so there should be no timeout even if a website is slow to respond. The main cause I know for getting timeout errors is when I send invalid Javascript code over to Firefox.

Last commands before timeout which I can see with strace:

write(3, "JSON.stringify( function(){ var res = repl.getAttr(17,\"busy
+\")\n; return { result: res }}())\n", 91) = 91
select(8, [3], NULL, NULL, {11, 0})     = 1 (in [3], left {10, 999993}
+)
read(3, "\"{\"result\":{\"result\":0,\"type\":null}}\"\n", 4096) = 38
select(8, [3], NULL, NULL, {11, 0})     = 1 (in [3], left {10, 964561}
+)
read(3, "repl> ", 4096)                 = 6
select(8, NULL, [3], NULL, {11, 0})     = 1 (out [3], left {10, 999993
+})
write(3, "JSON.stringify( function(){ var res = repl.getAttr(17,\"busy
+\")\n; return { result: res }}())\n", 91) = 91
select(8, [3], NULL, NULL, {11, 0})     = 1 (in [3], left {10, 997753}
+)
read(3, "\"{\"result\":{\"result\":0,\"type\":null}}\"\nrepl> ", 4096)
+ = 44
select(8, NULL, [3], NULL, {11, 0})     = 1 (out [3], left {10, 999993
+})
write(3, "JSON.stringify( function(){ var res = repl.getAttr(17,\"busy
+\")\n; return { result: res }}())\n", 91) = 91
select(8, [3], NULL, NULL, {11, 0})     = 1 (in [3], left {10, 997763}
+)
read(3, "\"{\"result\":{\"result\":0,\"type\":null}}\"\nrepl> ", 4096)
+ = 44
select(8, NULL, [3], NULL, {11, 0})     = 1 (out [3], left {10, 999992
+})
write(3, "JSON.stringify( function(){ var res = repl.getAttr(17,\"busy
+\")\n; return { result: res }}())\n", 91) = 91
select(8, [3], NULL, NULL, {11, 0})     = 1 (in [3], left {10, 998085}
+)
read(3, "\"{\"result\":{\"result\":0,\"type\":null}}\"\nrepl> ", 4096)
+ = 44
select(8, NULL, [3], NULL, {11, 0})     = 1 (out [3], left {10, 999992
+})
write(3, "JSON.stringify( function(){ var res = repl.getAttr(17,\"busy
+\")\n; return { result: res }}())\n", 91) = 91
select(8, [3], NULL, NULL, {11, 0})     = 1 (in [3], left {10, 997690}
+)
read(3, "\"{\"result\":{\"result\":0,\"type\":null}}\"\n", 4096) = 38
select(8, [3], NULL, NULL, {11, 0})     = 1 (in [3], left {10, 960641}
+)
read(3, "repl> ", 4096)                 = 6
select(8, NULL, [3], NULL, {11, 0})     = 1 (out [3], left {10, 999992
+})
write(3, "JSON.stringify( function(){ var res = repl.getAttr(17,\"busy
+\")\n; return { result: res }}())\n", 91) = 91
select(8, [3], NULL, NULL, {11, 0})     = 1 (in [3], left {10, 997790}
+)
read(3, "\"{\"result\":{\"result\":0,\"type\":null}}\"\nrepl> ", 4096)
+ = 44
select(8, NULL, [3], NULL, {11, 0})     = 1 (out [3], left {10, 999993
+})
write(3, "JSON.stringify( function(){ var res = repl.getAttr(17,\"busy
+\")\n; return { result: res }}())\n", 91) = 91
select(8, [3], NULL, NULL, {11, 0})     = 1 (in [3], left {10, 997765}
+)
read(3, "\"{\"result\":{\"result\":0,\"type\":null}}\"\nrepl> ", 4096)
+ = 44
select(8, NULL, [3], NULL, {11, 0})     = 1 (out [3], left {10, 999993
+})
write(3, "JSON.stringify( function(){ var res = repl.getAttr(17,\"busy
+\")\n; return { result: res }}())\n", 91) = 91
select(8, [3], NULL, NULL, {11, 0})     = 1 (in [3], left {10, 997764}
+)
read(3, "\"{\"result\":{\"result\":0,\"type\":null}}\"\nrepl> ", 4096)
+ = 44
select(8, NULL, [3], NULL, {11, 0})     = 1 (out [3], left {10, 999993
+})
write(3, "JSON.stringify( function(){ var res = repl.getAttr(17,\"busy
+\")\n; return { result: res }}())\n", 91) = 91
select(8, [3], NULL, NULL, {11, 0})     = 1 (in [3], left {10, 997768}
+)
read(3, "\"{\"result\":{\"result\":0,\"type\":null}}\"\nrepl> ", 4096)
+ = 44
select(8, NULL, [3], NULL, {11, 0})     = 1 (out [3], left {10, 999992
+})
write(3, "JSON.stringify( function(){ var res = repl.getAttr(17,\"busy
+\")\n; return { result: res }}())\n", 91) = 91
select(8, [3], NULL, NULL, {11, 0})     = 1 (in [3], left {10, 999993}
+)
read(3, "\"{\"result\":{\"result\":0,\"type\":null}}\"\nrepl> ", 4096)
+ = 44
select(8, NULL, [3], NULL, {11, 0})     = 1 (out [3], left {10, 999993
+})
write(3, "JSON.stringify( function(){ var res = repl.getAttr(17,\"busy
+\")\n; return { result: res }}())\n", 91) = 91
select(8, [3], NULL, NULL, {11, 0})     = 1 (in [3], left {10, 997789}
+)
read(3, "\"{\"result\":{\"result\":0,\"type\":null}}\"\nrepl> ", 4096)
+ = 44
select(8, NULL, [3], NULL, {11, 0})     = 1 (out [3], left {10, 999992
+})
write(3, "JSON.stringify( function(){ var res = repl.getAttr(17,\"busy
+\")\n; return { result: res }}())\n", 91) = 91
select(8, [3], NULL, NULL, {11, 0})     = 1 (in [3], left {10, 996842}
+)
read(3, "\"{\"result\":{\"result\":0,\"type\":null}}\"\nrepl> ", 4096)
+ = 44
select(8, NULL, [3], NULL, {11, 0})     = 1 (out [3], left {10, 999993
+})
write(3, "JSON.stringify( function(){ var res = repl.getAttr(17,\"busy
+\")\n; return { result: res }}())\n", 91) = 91
select(8, [3], NULL, NULL, {11, 0})     = 1 (in [3], left {10, 997698}
+)
read(3, "\"{\"result\":{\"result\":0,\"type\":null}}\"\n", 4096) = 38
select(8, [3], NULL, NULL, {11, 0})     = 1 (in [3], left {10, 960724}
+)
read(3, "repl> ", 4096)                 = 6
select(8, NULL, [3], NULL, {11, 0})     = 1 (out [3], left {10, 999993
+})
write(3, "JSON.stringify( function(){ var res = repl.getAttr(17,\"busy
+\")\n; return { result: res }}())\n", 91) = 91
select(8, [3], NULL, NULL, {11, 0})     = 0 (Timeout)
write(2, "command timed-out at /usr/local/share/perl/5.10.1/MozRepl/Cl
+ient.pm line 186\n", 77) = 77
[download]

This is weird and I don't know where that timeout comes from. Maybe it really is Firefox timing out as it is busy synchronously fetching some result. As you see in the trace, WWW::Mechanize::Firefox polls every second (or so) to see whether Firefox has fetched a page.

If it really is Net::Telnet, then you'll have to dive down:

$mech->repl->repl->client->{telnet}->timeout($new_timeout);
[download]