• Michael (22/22) Oct 04 2020 Dear all,
• Paul Backus (3/11) Oct 04 2020 Works fine for me using DMD 2.094.0 on Linux. What OS and
• Michael (3/18) Oct 04 2020 DMD64 D Compiler v2.094.0
• Michael (3/22) Oct 04 2020 I did not use any compiler flags, but just:
• Mathias LANG (3/22) Oct 04 2020 I cannot reproduce locally (macOS 10.15.6 too). How did you
• Michael (2/25) Oct 04 2020 I used the dmg file: dmd.2.094.0.dmg
• Michael (6/32) Oct 04 2020 I reinstalled using the installation script (install.sh) and now
• Mathias LANG (5/13) Oct 04 2020 I think there might have been a mismatch between the compiler
• Imperatorn (3/7) Oct 04 2020 I have tried my best to make it fail, but can't. Maybe it's

Michael <trash can.edu> writes:

Dear all,

Sorry for the potentially stupid question, but I'm a complete 
newbie to D. Why does compiling the following trivial code fail?

import std.stdio;

void main()
{
     writeln(3.14);
}

Error message:

/Library/D/dmd/src/phobos/std/format.d(1601): Error: pure 
function std.format.FormatSpec!char.FormatSpec.toString cannot 
call impure function 
std.format.FormatSpec!char.FormatSpec.toString!(Appender!string).toString
/Library/D/dmd/src/phobos/std/format.d(478): Error: template 
instance std.format.FormatSpec!char error instantiating
/Library/D/dmd/src/phobos/std/stdio.d(1590):        instantiated 
from here: formattedWrite!(LockingTextWriter, char, double)
/Library/D/dmd/src/phobos/std/stdio.d(3927):        instantiated 
from here: write!(double, char)
test1.d(5):        instantiated from here: writeln!double

Cheers,
Michael

Paul Backus <snarwin gmail.com> writes:

On Sunday, 4 October 2020 at 16:48:24 UTC, Michael wrote:
 Dear all,

 Sorry for the potentially stupid question, but I'm a complete 
 newbie to D. Why does compiling the following trivial code fail?

 import std.stdio;

 void main()
 {
     writeln(3.14);
 }

Works fine for me using DMD 2.094.0 on Linux. What OS and 
compiler version are you using, and how did you install DMD?

Michael <trash can.edu> writes:

On Sunday, 4 October 2020 at 17:01:44 UTC, Paul Backus wrote:
 On Sunday, 4 October 2020 at 16:48:24 UTC, Michael wrote:
 Dear all,

 Sorry for the potentially stupid question, but I'm a complete 
 newbie to D. Why does compiling the following trivial code 
 fail?

 import std.stdio;

 void main()
 {
     writeln(3.14);
 }

 Works fine for me using DMD 2.094.0 on Linux. What OS and 
 compiler version are you using, and how did you install DMD?

DMD64 D Compiler v2.094.0
on macOS 10.15.6

Michael <trash can.edu> writes:

On Sunday, 4 October 2020 at 17:05:33 UTC, Michael wrote:
 On Sunday, 4 October 2020 at 17:01:44 UTC, Paul Backus wrote:
 On Sunday, 4 October 2020 at 16:48:24 UTC, Michael wrote:
 Dear all,

 Sorry for the potentially stupid question, but I'm a complete 
 newbie to D. Why does compiling the following trivial code 
 fail?

 import std.stdio;

 void main()
 {
     writeln(3.14);
 }

 Works fine for me using DMD 2.094.0 on Linux. What OS and 
 compiler version are you using, and how did you install DMD?

 DMD64 D Compiler v2.094.0
 on macOS 10.15.6

I did not use any compiler flags, but just:
dmd test1.d

Mathias LANG <geod24 gmail.com> writes:

On Sunday, 4 October 2020 at 17:05:33 UTC, Michael wrote:
 On Sunday, 4 October 2020 at 17:01:44 UTC, Paul Backus wrote:
 On Sunday, 4 October 2020 at 16:48:24 UTC, Michael wrote:
 Dear all,

 Sorry for the potentially stupid question, but I'm a complete 
 newbie to D. Why does compiling the following trivial code 
 fail?

 import std.stdio;

 void main()
 {
     writeln(3.14);
 }

 Works fine for me using DMD 2.094.0 on Linux. What OS and 
 compiler version are you using, and how did you install DMD?

 DMD64 D Compiler v2.094.0
 on macOS 10.15.6

I cannot reproduce locally (macOS 10.15.6 too). How did you 
install DMD ?

Michael <trash can.edu> writes:

On Sunday, 4 October 2020 at 17:37:52 UTC, Mathias LANG wrote:
 On Sunday, 4 October 2020 at 17:05:33 UTC, Michael wrote:
 On Sunday, 4 October 2020 at 17:01:44 UTC, Paul Backus wrote:
 On Sunday, 4 October 2020 at 16:48:24 UTC, Michael wrote:
 Dear all,

 Sorry for the potentially stupid question, but I'm a 
 complete newbie to D. Why does compiling the following 
 trivial code fail?

 import std.stdio;

 void main()
 {
     writeln(3.14);
 }

 Works fine for me using DMD 2.094.0 on Linux. What OS and 
 compiler version are you using, and how did you install DMD?

 DMD64 D Compiler v2.094.0
 on macOS 10.15.6

 I cannot reproduce locally (macOS 10.15.6 too). How did you 
 install DMD ?

I used the dmg file: dmd.2.094.0.dmg

Michael <trash can.edu> writes:

On Sunday, 4 October 2020 at 17:43:13 UTC, Michael wrote:
 On Sunday, 4 October 2020 at 17:37:52 UTC, Mathias LANG wrote:
 On Sunday, 4 October 2020 at 17:05:33 UTC, Michael wrote:
 On Sunday, 4 October 2020 at 17:01:44 UTC, Paul Backus wrote:
 On Sunday, 4 October 2020 at 16:48:24 UTC, Michael wrote:
 Dear all,

 Sorry for the potentially stupid question, but I'm a 
 complete newbie to D. Why does compiling the following 
 trivial code fail?

 import std.stdio;

 void main()
 {
     writeln(3.14);
 }

 Works fine for me using DMD 2.094.0 on Linux. What OS and 
 compiler version are you using, and how did you install DMD?

 DMD64 D Compiler v2.094.0
 on macOS 10.15.6

 I cannot reproduce locally (macOS 10.15.6 too). How did you 
 install DMD ?

 I used the dmg file: dmd.2.094.0.dmg

I reinstalled using the installation script (install.sh) and now 
it works. Still don't know why the dmg-based intstallation did 
not work.
https://dlang.org/install.html

Anyway, thanks for your responses!

Mathias LANG <geod24 gmail.com> writes:

On Sunday, 4 October 2020 at 18:02:11 UTC, Michael wrote:
 On Sunday, 4 October 2020 at 17:43:13 UTC, Michael wrote:
 [...]
 I used the dmg file: dmd.2.094.0.dmg

 I reinstalled using the installation script (install.sh) and 
 now it works. Still don't know why the dmg-based intstallation 
 did not work.
 https://dlang.org/install.html

 Anyway, thanks for your responses!

I think there might have been a mismatch between the compiler 
used, and the Phobos library used. This might happen if you used 
multiple sources for installation, e.g.  brew / macports / dmg 
(install script is self contained and never affected).

Imperatorn <johan_forsberg_86 hotmail.com> writes:

On Sunday, 4 October 2020 at 16:48:24 UTC, Michael wrote:
 Dear all,

 Sorry for the potentially stupid question, but I'm a complete 
 newbie to D. Why does compiling the following trivial code fail?

 [...]

I have tried my best to make it fail, but can't. Maybe it's 
something with the combination of dmd64 and MACOS?