> cmake ../ -DCMAKE_INSTALL_PREFIX=/usr/local/midas

good timing, I am working on cmake for manalyzer and rootana and I have not tested
the install prefix business.

now I know to test it for all 3 packages.

I will also change find_package(Midas) slightly, (see my other message here),
I hope you can confirm that I do not break it for you.

K.O.

> cmake ../ -DCMAKE_INSTALL_PREFIX=/usr/local/midas
> Is the cmake setup not relocatable? This is new and was working until recently:

Indeed. Not relocatable. This is because we do not install the header files.

When you use the CMAKE_INSTALL_PREFIX, you get MIDAS "installed" in:

prefix/lib
prefix/bin
$MIDASSYS/include <-- this is the source tree and so not "relocatable"!

Before, this was kludged and cmake did not complain about it.

Now I changed cmake to handle the include path "the cmake way", and now it knows to complain about it.

I am not sure how to fix this: we have a conflict between:

- our normal way of using midas (include $MIDASSYS/include, link $MIDASSYS/lib, run $MIDASSYS/bin)
- the cmake way (packages *must be installed* or else! but I do like install(EXPORT)!)
- and your way (midas include files are in $MIDASSYS/include, everything else is in your special location)

I think your case is strange. I am curious why you want midas libraries to be in prefix/lib instead of in 
$MIDASSYS/lib (in the source tree), but are happy with header files remaining in the source tree.

K.O.

> > cmake ../ -DCMAKE_INSTALL_PREFIX=/usr/local/midas
> > Is the cmake setup not relocatable? This is new and was working until recently:
> 
> Indeed. Not relocatable. This is because we do not install the header files.
> 
> When you use the CMAKE_INSTALL_PREFIX, you get MIDAS "installed" in:
> 
> prefix/lib
> prefix/bin
> $MIDASSYS/include <-- this is the source tree and so not "relocatable"!
> 
> Before, this was kludged and cmake did not complain about it.
> 
> Now I changed cmake to handle the include path "the cmake way", and now it knows to complain about it.
> 
> I am not sure how to fix this: we have a conflict between:
> 
> - our normal way of using midas (include $MIDASSYS/include, link $MIDASSYS/lib, run $MIDASSYS/bin)
> - the cmake way (packages *must be installed* or else! but I do like install(EXPORT)!)
> - and your way (midas include files are in $MIDASSYS/include, everything else is in your special location)
> 
> I think your case is strange. I am curious why you want midas libraries to be in prefix/lib instead of in 
> $MIDASSYS/lib (in the source tree), but are happy with header files remaining in the source tree.
> 
> K.O.

We do it this way, since the lib and bin needs to be in a place where standard users have no access to. 
If I think an all other packages I am working with, e.g. ROOT, the includes are also installed under CMAKE_INSTALL_PREFIX. 
Up until recently there was no issue to work with CMAKE_INSTALL_PREFIX, accepting that the includes stay under 
$MIDASSYS/include, even though this is not quite the standard way, but no problem here. Anyway, since CMAKE_INSTALL_PREFIX 
is a standard option from cmake, I think things should not "break" if you want to use it.

A.S.

> > > cmake ../ -DCMAKE_INSTALL_PREFIX=/usr/local/midas
> > > Is the cmake setup not relocatable? This is new and was working until recently:
> > Not relocatable. This is because we do not install the header files.
> 
> We do it this way, since the lib and bin needs to be in a place where standard users have no access to. 

hmm... i did not get this. "needs to be in a place where standard users have no access to". what do you
mean by this? you install midas in a secret location to prevent somebody from linking to it?

> If I think an all other packages I am working with, e.g. ROOT, the includes are also installed under CMAKE_INSTALL_PREFIX.

cmake and other frameworks tend to be like procrustean beds (https://en.wikipedia.org/wiki/Procrustes),
pre-cmake packages never quite fit perfectly, and either the legs or the heads get cut off. post-cmake packages
are constructed to fit the bed, whether it makes sense or not.

given how this situation is known since antiquity, I doubt we will solve it today here.

(I exercise my freedom of speech rights to state that I object being put into
such situations. And I would like to have it clear that I hate cmake (ask me why)).

>
> Up until recently there was no issue to work with CMAKE_INSTALL_PREFIX, accepting that the includes stay under 
> $MIDASSYS/include, even though this is not quite the standard way, but no problem here.
>

I think a solution would be to add install rules for include files. There will be a bit of trouble,
normal include path is $MIDASSYS/include,$MIDASSYS/mxml,$MIDASSYS/mjson,etc, after installing
it will be $CMAKE_INSTALL_PREFIX/include (all header files from different git submodules all
dumped into one directory). I do not know what problems will show up from that.

I think if midas is used as a subproject of a bigger project, this is pretty much required
(and I have seen big experiments, like STAR and ND280, do this type of stuff with CMT,
another horror and the historical precursor of cmake)

The problem is that we do not have any super-project like this here, so I cannot ever
be sure that I have done everything correctly. cmake itself can be helpful, like
in the current situation where it told us about a problem. but I will never trust
cmake completely, I see cmake do crazy and unreasonable things way too often.

One solution would be for you or somebody else to contribute such a cmake super-project,
that would build midas as a subproject, install it with a CMAKE_INSTALL_PREFIX and
try to link some trivial frontend or analyzer to check that everything is installed
correctly. It would become an example for "how to use midas as a subproject").
Ideally, it should be usable in a bitbucket automatic build (assuming bitbucket
has correct versions of cmake, which it does not half the time).

P.S. I already spent half-a-week tinkering with cmake rules, only to discover
that I broke a kludge that allows you to do something strange (if I have it right,
the CMAKE_PREFIX_INSTALL code is your contribution). This does not encourage
 me to tinker with cmake even more. who knows against what other
kludge I bump into. (oh, yes, I know, I already bumped into the nonsense
find_package(Midas) implementation).

K.O.

> > > > cmake ../ -DCMAKE_INSTALL_PREFIX=/usr/local/midas
> > > > Is the cmake setup not relocatable? This is new and was working until recently:
> > > Not relocatable. This is because we do not install the header files.
> > 
> > We do it this way, since the lib and bin needs to be in a place where standard users have no access to. 
> 
> hmm... i did not get this. "needs to be in a place where standard users have no access to". what do you
> mean by this? you install midas in a secret location to prevent somebody from linking to it?
> 

This was a wrong wording from my side. We do not want the the users have write access to the midas installation libs and bins.
I have submitted the pull request which should resolve this without interfere with your usage.
Hope this will resolve the issue.

> > > > > cmake ../ -DCMAKE_INSTALL_PREFIX=/usr/local/midas
> > > > > Is the cmake setup not relocatable? This is new and was working until recently:
> > > > Not relocatable. This is because we do not install the header files.
> > > 
> > > We do it this way, since the lib and bin needs to be in a place where standard users have no access to. 
> > 
> > hmm... i did not get this. "needs to be in a place where standard users have no access to". what do you
> > mean by this? you install midas in a secret location to prevent somebody from linking to it?
> > 
> 
> This was a wrong wording from my side. We do not want the the users have write access to the midas installation libs and bins.
> I have submitted the pull request which should resolve this without interfere with your usage.
> Hope this will resolve the issue.

Excellent. I think it is good to have midas "install" in a sane manner.

But I still struggle to understand what you do. Presumably you can "install" midas
in the "midas account", which is not writable by the experiment and user accounts.
Then it does not matter if you "install" it in it's build directory (like we do)
or in some other location (like you do now).

This does not work of course if you only have one account, so do you build midas
as root? or install it as root?

I do ask because in the current computing world, doing things as root requires
a certain amount of trust, which may not be there anymore, see the recent "supply side" attacks
against python packages, solar winds hack, linux kernel malicious patches from umn, etc.

Personally, I do not want to answer questions "is midas safe to run as root?",
"can I trust the midas install scripts to run as root?" and certainly I do not want to hear
about "I installed midas and 100 other packages as root and got hacked 7 days later".

(and running midas as root was never safe. neither mhttpd nor mserver will pass
a security audit).

Anyhow, looks like I will look at cmake again next week. Right now I have a major
breakthrough in the ALPHA-g experiment, my big 96-port Juniper switch suddenly
has working ethernet flow control and I can record data at 600 Mbytes/sec without
any UDP packet loss. Above that, my event builder explodes. I want to fix it and get
it up to 1000 Mbytes/sec, the limit of my 10gige network link. (In this system I do not
have the disk subsystem to record data at this rate, but I have build 8-disk ZFS arrays
that would sink it, no problem). And the day has come when I ran out of CPU cores.
The UDP packet receivers are multithreaded, the event builder is multithreaded and I am using
all 4 of the available cores (intel cpu). As soon as I can get a rackmounted AMD Ryzen
or Threadripper machine, we will likely upgrade. (need at least one more CPU core to run
the online analyzer!). Exciting.

K.O.

> > > > > > cmake ../ -DCMAKE_INSTALL_PREFIX=/usr/local/midas
> > > > > > Is the cmake setup not relocatable? This is new and was working until recently:
> > > > > Not relocatable. This is because we do not install the header files.
> > > > 
> > > > We do it this way, since the lib and bin needs to be in a place where standard users have no access to. 
> > > 
> > > hmm... i did not get this. "needs to be in a place where standard users have no access to". what do you
> > > mean by this? you install midas in a secret location to prevent somebody from linking to it?
> > > 
> > 
> > This was a wrong wording from my side. We do not want the the users have write access to the midas installation libs and bins.
> > I have submitted the pull request which should resolve this without interfere with your usage.
> > Hope this will resolve the issue.
> 
> Excellent. I think it is good to have midas "install" in a sane manner.
> 
> But I still struggle to understand what you do. Presumably you can "install" midas
> in the "midas account", which is not writable by the experiment and user accounts.
> Then it does not matter if you "install" it in it's build directory (like we do)
> or in some other location (like you do now).
> 
> This does not work of course if you only have one account, so do you build midas
> as root? or install it as root?
> 

We work the following way: there is a production Midas under let's say /usr/local/midas (make install as sudo/root). This is for the running experiment. Since we are doing muSR, we 
have experiments on a daily base, rather than month and years as it is the case for a particle physics experiment. Now, still we would like to test updates, new features of Midas on 
the same machine. For this we us the repo directly. If we are happy with the new feature, and fixes, we again do a 'make install' and hence freeze for the production a specific 
snapshot. Of course we could use various local copies of the Midas repo, but over the last years this approach was very convenient and productive. Hope this explains a bit better 
why we want to work with a CMAKE_INSTALL_PREFIX.

AS

big thanks to Andreas S. for getting most of this figured out. I now understand
much better how cmake installs things and how it generates config files, both
find_package(midas) style and install(export) style.

with the latest updates, CMAKE_INSTALL_PREFIX should work correctly. I now understand how it works,
how to use it and how to test it, it should not break again.

for posterity, my commends to Andreas's pull request:

thank you for providing this code, it was very helpful. at the end I implemented things slightly differently. It took me a while to understand that I have to provide 2 “install” modes, for your case, I need to 
“install” the header files and everything works “the cmake way”, for our normal case, we use include files in-place and have to include all the git submodules to the include path. I am quite happy with the 
result. K.O.

K.O.

Dear Konstantin,

I have tried your adopted version. You did already quite a job which is more consistent than what I was suggesting.
Yet, I still have a problem (git sha2 2d3872dfd31) when starting on a clean system (i.e. no midas present yet): 
Without CMAKE_INSTALL_PREFIX set, everything is fine. 
However, when setting CMAKE_INSTALL_PREFIX, I get the following error message on the build level (cmake --build ./ -- VERBOSE=1) from the manalyzer:

[ 32%] Building CXX object manalyzer/CMakeFiles/manalyzer.dir/manalyzer.cxx.o
cd /home/l_musr_tst/Tmp/midas/build/manalyzer && /usr/bin/c++  -DHAVE_FTPLIB -DHAVE_MIDAS -DHAVE_ROOT_HTTP -DHAVE_THTTP_SERVER -DHAVE_TMFE -DHAVE_ZLIB -D_LARGEFILE64_SOURCE -I/home/l_musr_tst/Tmp/midas/manalyzer -I/usr/local/root/include  -O2 -g -Wall -Wformat=2 -Wno-format-nonliteral -Wno-strict-aliasing -Wuninitialized -Wno-unused-function -std=c++11 -pipe -fsigned-char -pthread -DHAVE_ROOT -std=gnu++11 -o CMakeFiles/manalyzer.dir/manalyzer.cxx.o -c /home/l_musr_tst/Tmp/midas/manalyzer/manalyzer.cxx
In file included from /home/l_musr_tst/Tmp/midas/manalyzer/manalyzer.cxx:14:0:
/home/l_musr_tst/Tmp/midas/manalyzer/manalyzer.h:13:21: fatal error: midasio.h: No such file or directory
 #include "midasio.h"
                     ^
compilation terminated.

Obviously, still some include paths are missing. I tried quickly to see if an easy fix is possible, but I failed.

Question: is it possible to use manalyzer without midas? I am asking since the MIDAS_FOUND flag is confusing me.

> big thanks to Andreas S. for getting most of this figured out. I now understand
> much better how cmake installs things and how it generates config files, both
> find_package(midas) style and install(export) style.
> 
> with the latest updates, CMAKE_INSTALL_PREFIX should work correctly. I now understand how it works,
> how to use it and how to test it, it should not break again.
> 
> for posterity, my commends to Andreas's pull request:
> 
> thank you for providing this code, it was very helpful. at the end I implemented things slightly differently. It took me a while to understand that I have to provide 2 “install” modes, for your case, I need to 
> “install” the header files and everything works “the cmake way”, for our normal case, we use include files in-place and have to include all the git submodules to the include path. I am quite happy with the 
> result. K.O.
> 
> K.O.

cmake check and mate in 1 move. please help.

the midas cmake file has a typo in the ROOT_CXX_FLAGS, I fixed it and now I am dead in the 
water, need help from cmake experts and pushers.

On Ubuntu:
ROOT_CXX_FLAGS has -std=c++14
midas cmake defines -std=gnu++11 (never mind that I asked for c++11, not "c++11 with GNU 
extensions")

the two compiler flags collide and the build explodes, the best I can tell c++11 prevails 
and ROOT header files blow up because they expect c++14.

if I remove the midas cmake request for c++11, -std=gnu++11 is gone, there is no conflict 
with ROOT C++14 request and the build works just fine.

but now it explodes on CentOS-7 because by default, c++11 is not enabled. (include <mutex> 
blows up).

what a mess.

K.O.

> cmake check and mate in 1 move. please help.
> -std=c++11 and -std=c++14 collision...

I have a solution implemented for this, I am not happy with it, Stefan is not happy with it. See 
discussion: https://bitbucket.org/tmidas/midas/commits/50a15aa70a4fe3927764605e8964b55a3bb1732b

K.O.

> > cmake check and mate in 1 move. please help.
> > -std=c++11 and -std=c++14 collision...
> 
> I have a solution implemented for this, I am not happy with it, Stefan is not happy with it. See 
> discussion: https://bitbucket.org/tmidas/midas/commits/50a15aa70a4fe3927764605e8964b55a3bb1732b
>

I figured it out, solution is to use:

target_compile_features(midas PUBLIC cxx_std_11)

this is how it works:

- centos-7 (g++ has c++11 off by default): -std=gnu++11 is added automatically (not -std=c++11, but 
probably correct, as some c++11 functions were available as gnu extensions)
- ubuntu-20.04 LTS without ROOT: nothing added (I guess correct, g++ has c++11 is enabled by default)
- ubuntu-20.04 LTS with -std=c++14 from ROOT: nothing added, c++14 as requested by ROOT is in affect.
- macos without ROOT: -std=gnu++11 is added automatically
- macos with -std=c++11 from ROOT: ditto, so both -std=c++11 and -std=gnu++11 are present in this order, 
wrong-ish, but works.

and good luck figuring this out just from cmake documentation:
https://cmake.org/cmake/help/latest/command/target_compile_features.html

K.O.

> Complile including ROOT throws an error with ROOT 6.18/04 on Fedora 31 ...
> /usr/include/root/ROOT/RStringView.hxx:32:37: error: ‘experimental’ in namespace ‘std’ ...

I was puzzled by this error about "experimental" in ROOT header files.

All ROOT kits that I have are configured and built with c++11, and I do not see this error. I now guess that you
only saw this on Fedora 31 with gcc 9 and ROOT that was configured for c++14 or c++17.

We now realize that MIDAS cmake does not use the ROOT CFLAGS when building code that uses ROOT,
and this is probably a mistake. Stefan added a fix to use ROOT CFLAGS to build the analyzer,
but I am not sure if this is sufficient, rmana and rmlogger probably also should use the ROOT CFLAGS.

In any case, we are setup for an eventual collision between MIDAS CFLAGS (-std=gnu++11) and ROOT CFLAGS (-std=something else).

K.O.

> In any case, we are setup for an eventual collision between MIDAS CFLAGS (-std=gnu++11) and ROOT CFLAGS (-std=something else).

Are there good reasons to not compile MIDAS with set(CMAKE_CXX_STANDARD 14)? So far this was an easier "fix" for me than to recompile ROOT with c++11.

> > In any case, we are setup for an eventual collision between MIDAS CFLAGS (-std=gnu++11) and ROOT CFLAGS (-std=something else).
> 
> Are there good reasons to not compile MIDAS with set(CMAKE_CXX_STANDARD 14)? So far this was an easier "fix" for me than to recompile ROOT with c++11.

Yes. We agreed to base MIDAS on C++11, not C++14, since C++11 is available on all relevant systems. By putting that requirement explicitly into the CMake file, we know that it 
correctly compiles with C++11. Of course feel free to overwrite this in your local installation.

Stefan

> > In any case, we are setup for an eventual collision between MIDAS CFLAGS (-std=gnu++11) and ROOT CFLAGS (-std=something else).
> 
> Are there good reasons to not compile MIDAS with set(CMAKE_CXX_STANDARD 14)? So far this was an easier "fix" for me than to recompile ROOT with c++11.

We already have trouble enough even with requiring C++11:

We still run a number of SL6 DAQ stations at TRIUMF, and it is well known that SL6 gcc does not even do c++11.

The suggested solution to "simply just use the devtoolset-8" compilers turned out to be missing a critical 32-bit
library and cannot build midas for 32-bit VME processors. (straight or cross-compiled).

(A solution for this can be kludged using unofficial packages: https://midas.triumf.ca/elog/Midas/1748)

No, we cannot "just upgrade" SL6 and no, we cannot "just replace" the 32-bit-only VME processors.

If we move the midas requirements from c++11 to c++14, again, we have to see what compilers
are available on what platforms, and I am sure again we will miss some important case.

And then, where does this train stop?

I see c++17 has some really nice to use improvements. And I see c++20 added even some more nice improvements.

I say we follow ROOT: https://root.cern.ch/supported-platforms

> Supported Platforms
> ROOT 6
> The compiler needs to support -std=c++11 to be able to build version 6.

K.O.

> > In any case, we are setup for an eventual collision between MIDAS CFLAGS (-std=gnu++11) and ROOT CFLAGS (-std=something else).
> 
> Are there good reasons to not compile MIDAS with set(CMAKE_CXX_STANDARD 14)? So far this was an easier "fix" for me than to recompile ROOT with c++11.

Per  https://root.cern.ch/supported-platforms, ROOTv6 is C++11.

Binary kits distributed from root.cern.ch seem to be built with c++11.

Where does ROOT built with c++14 come from?

K.O.

While upgrading to the latest MIDAS version

MIDAS version: 2.1 GIT revision: Tue Dec 31 17:40:14 2019 +0100 - midas-2019-09-i-1-gd93944ce-dirty on branch develop

ODB version: 3

I encountered two issues using cmake

1. on machines with NVIDIA drivers:

(nvml.h doesn't seem to be part of the standard nvidia driver package.)

2. Complile including ROOT throws an error with ROOT 6.12/06 on Centos7 and with ROOT 6.18/04 on Fedora 31:

A workaround (which works for me) is to compile with

cmake .. -DNO_ROOT=1 -DNO_NVIDIA=1

(please post messages in "plain" mode, they are much easier to answer)

- nvidia problems - this code was contributed by Joseph (I think?), with luck he will look into 
this problem.

- ROOT problem - it looks like the error is thrown by the ROOT header files, has nothing to do 
with MIDAS?

So what ROOT are you using? I recommend installing ROOT by following instructions at 
root.cern.ch.

Perhaps you used the ROOT packages from the EPEL repository? I have seen trouble with 
those packages before (miscompiled; important optional features turned off; very old 
versions; etc).

P.S.

Historically, ROOT has caused so many reports of "cannot build midas" that I consistently 
vote to "remove ROOT support from MIDAS". But Stefan's code for writing MIDAS data into 
ROOT files is so neat, cannot throw it away. And some people do use it. So at the latest MIDAS 
bash this Summer we decided to keep it.

(Only build targets to use ROOT are the rmlogger executable and the rmana.o object file (and 
it's one-man-army library)).

But.

In the past, one could use "make -k" to get past the errors caused by ROOT, everything will 
get built and installed, except for the code that failed to build.

Now with cmake, it is "all or nothing", if there is any compilation error, nothing gets installed 
into the "bin" directory. So one must discover and use "NO_ROOT=1" (which becomes sticky 
until the next "make cclean". Some people are not used to sticky "make" options, I just got 
burned by this very thing last week).

Perhaps there is a way to tell cmake to ignore compile errors for rmlogger and rmana.


K.O.



<p>&nbsp;</p>

<table align="center" cellspacing="1" style="border:1px solid #486090; width:98%">
	<tbody>
		<tr>
			<td style="background-color:#486090">Peter Kunz wrote:</td>
		</tr>
		<tr>
			<td style="background-color:#FFFFB0">
			<p>While upgrading to the latest MIDAS version</p>

			<p>MIDAS version: 2.1 GIT revision: Tue Dec 31 17:40:14 2019 +0100 - midas-
2019-09-i-1-gd93944ce-dirty on branch develop</p>

			<p>ODB version: 3</p>

			<p>I encountered two issues using cmake</p>

			<p>1. on machines with NVIDIA drivers:</p>

			<div style="background:#eee;border:1px solid #ccc;padding:5px 
10px;">nvml.h: no such file or directory</div>

			<p>(nvml.h doesn&#39;t seem to be part of the standard nvidia driver 
package.)</p>

			<p>2. Complile including ROOT throws an error with ROOT 6.12/06 on Centos7 
and with ROOT 6.18/04 on Fedora 31:</p>

			<div style="background:#eee;border:1px solid #ccc;padding:5px 10px;">[ 29%] 
Building CXX object CMakeFiles/rmana.dir/src/mana.cxx.o In file included from 
/usr/include/root/TString.h:28, from /usr/include/root/TCollection.h:29, from 
/usr/include/root/TSeqCollection.h:25, from /usr/include/root/TList.h:25, from 
/usr/include/root/TQObject.h:40, from /usr/include/root/TApplication.h:30, from 
/home/pkunz/packages/midas/src/mana.cxx:60:</div>

			<div style="background:#eee;border:1px solid #ccc;padding:5px 
10px;">/usr/include/root/ROOT/RStringView.hxx:32:37: error: &lsquo;experimental&rsquo; in 
namespace &lsquo;std&rsquo; does not name a type 32 | using basic_string_view = 
::std::experimental::basic_string_view&lt;_CharT,_Traits&gt;;</div>

			<p>A workaround (which works for me) is to compile with</p>

			<p><tt>cmake .. -DNO_ROOT=1 -DNO_NVIDIA=1</tt></p>
			</td>
		</tr>
	</tbody>
</table>

<p>&nbsp;</p>

Re: ROOT problem

I looked into how my ROOT based MIDAS analyzer compiles. It is using the flag -std=c++14.
MIDAS cmake compiles with -std=gnu++11 with the result:

 29%] Building CXX object CMakeFiles/rmana.dir/src/mana.cxx.o
/usr/bin/c++  -D_LARGEFILE64_SOURCE -I/home/pkunz/packages/midas/include -I/home/pkunz/packages/midas/mxml -I/usr/include/root  -O2 -g -DNDEBUG   -DHAVE_ZLIB -DHAVE_FTPLIB -Wall -Wformat=2 -Wno-format-nonliteral -Wno-strict-aliasing -Wuninitialized -Wno-unused-function -DHAVE_ROOT -std=gnu++11 -o CMakeFiles/rmana.dir/src/mana.cxx.o -c /home/pkunz/packages/midas/src/mana.cxx
In file included from /usr/include/root/TString.h:28,
                 from /usr/include/root/TCollection.h:29,
                 from /usr/include/root/TSeqCollection.h:25,
                 from /usr/include/root/TList.h:25,
                 from /usr/include/root/TQObject.h:40,
                 from /usr/include/root/TApplication.h:30,
                 from /home/pkunz/packages/midas/src/mana.cxx:60:
/usr/include/root/ROOT/RStringView.hxx:32:37: error: ‘experimental’ in namespace ‘std’ does not name a type
   32 |    using basic_string_view = ::std::experimental::basic_string_view<_CharT,_Traits>;


If I change this to

/usr/bin/c++  -D_LARGEFILE64_SOURCE -I/home/pkunz/packages/midas/include -I/home/pkunz/packages/midas/mxml -I/usr/include/root  -O2 -g -DNDEBUG   -DHAVE_ZLIB -DHAVE_FTPLIB -Wall -Wformat=2 -Wno-format-nonliteral -Wno-strict-aliasing -Wuninitialized -Wno-unused-function -DHAVE_ROOT -std=c++14 -o CMakeFiles/rmana.dir/src/mana.cxx.o -c /home/pkunz/packages/midas/src/mana.cxx

it compiles without error. I hope this helps. 






> (please post messages in "plain" mode, they are much easier to answer)
> 
> - nvidia problems - this code was contributed by Joseph (I think?), with luck he will look into 
> this problem.
> 
> - ROOT problem - it looks like the error is thrown by the ROOT header files, has nothing to do 
> with MIDAS?
> 
> So what ROOT are you using? I recommend installing ROOT by following instructions at 
> root.cern.ch.
> 
> Perhaps you used the ROOT packages from the EPEL repository? I have seen trouble with 
> those packages before (miscompiled; important optional features turned off; very old 
> versions; etc).
> 
> P.S.
> 
> Historically, ROOT has caused so many reports of "cannot build midas" that I consistently 
> vote to "remove ROOT support from MIDAS". But Stefan's code for writing MIDAS data into 
> ROOT files is so neat, cannot throw it away. And some people do use it. So at the latest MIDAS 
> bash this Summer we decided to keep it.
> 
> (Only build targets to use ROOT are the rmlogger executable and the rmana.o object file (and 
> it's one-man-army library)).
> 
> But.
> 
> In the past, one could use "make -k" to get past the errors caused by ROOT, everything will 
> get built and installed, except for the code that failed to build.
> 
> Now with cmake, it is "all or nothing", if there is any compilation error, nothing gets installed 
> into the "bin" directory. So one must discover and use "NO_ROOT=1" (which becomes sticky 
> until the next "make cclean". Some people are not used to sticky "make" options, I just got 
> burned by this very thing last week).
> 
> Perhaps there is a way to tell cmake to ignore compile errors for rmlogger and rmana.
> 
> 
> K.O.
> 
> 
> 
> <p>&nbsp;</p>
> 
> <table align="center" cellspacing="1" style="border:1px solid #486090; width:98%">
> 	<tbody>
> 		<tr>
> 			<td style="background-color:#486090">Peter Kunz wrote:</td>
> 		</tr>
> 		<tr>
> 			<td style="background-color:#FFFFB0">
> 			<p>While upgrading to the latest MIDAS version</p>
> 
> 			<p>MIDAS version: 2.1 GIT revision: Tue Dec 31 17:40:14 2019 +0100 - midas-
> 2019-09-i-1-gd93944ce-dirty on branch develop</p>
> 
> 			<p>ODB version: 3</p>
> 
> 			<p>I encountered two issues using cmake</p>
> 
> 			<p>1. on machines with NVIDIA drivers:</p>
> 
> 			<div style="background:#eee;border:1px solid #ccc;padding:5px 
> 10px;">nvml.h: no such file or directory</div>
> 
> 			<p>(nvml.h doesn&#39;t seem to be part of the standard nvidia driver 
> package.)</p>
> 
> 			<p>2. Complile including ROOT throws an error with ROOT 6.12/06 on Centos7 
> and with ROOT 6.18/04 on Fedora 31:</p>
> 
> 			<div style="background:#eee;border:1px solid #ccc;padding:5px 10px;">[ 29%] 
> Building CXX object CMakeFiles/rmana.dir/src/mana.cxx.o In file included from 
> /usr/include/root/TString.h:28, from /usr/include/root/TCollection.h:29, from 
> /usr/include/root/TSeqCollection.h:25, from /usr/include/root/TList.h:25, from 
> /usr/include/root/TQObject.h:40, from /usr/include/root/TApplication.h:30, from 
> /home/pkunz/packages/midas/src/mana.cxx:60:</div>
> 
> 			<div style="background:#eee;border:1px solid #ccc;padding:5px 
> 10px;">/usr/include/root/ROOT/RStringView.hxx:32:37: error: &lsquo;experimental&rsquo; in 
> namespace &lsquo;std&rsquo; does not name a type 32 | using basic_string_view = 
> ::std::experimental::basic_string_view&lt;_CharT,_Traits&gt;;</div>
> 
> 			<p>A workaround (which works for me) is to compile with</p>
> 
> 			<p><tt>cmake .. -DNO_ROOT=1 -DNO_NVIDIA=1</tt></p>
> 			</td>
> 		</tr>
> 	</tbody>
> </table>
> 
> <p>&nbsp;</p>