I am building a new recipe which contains python.
when doing bitbake foo, it pass without problem.
when building overall image, it shows this error:
nothing provides /bin/env needed by foo
Change the shebang of the python file from '/bin/env python' to the real path (e.g. /usr/bin/python'.
Related
I am very new to Coq.
In our project, we switched to using the coq_makefile utility and came across the following problem.
Stepping through a proof script would result in this error:
Require Import comparable.
Error:
The file /Users/ayman/open-source/regex-reexamined-coq/comparable.vo contains library
Top.comparable and not library comparable
Our _CoqProject file is very simple (maybe that is the problem), it just lists all the files in the project https://github.com/awalterschulze/regex-reexamined-coq/blob/2c865aecc00276e0a926c1729cc35553c1cc6767/_CoqProject.
Coq libraries have a logical path. For example, files from the standard library all have a logical path starting with Coq. In your case, you did not specify anything about the logical path, so Coq arbitrarily puts the compiled files into a path starting with Top. Later, when trying to load the file, Coq compares the logical path Top to the physical path . and complains about the discrepancy.
The simplest fix is to add the following line to your _CoqProject file: -R . Top. Option -R maps a physical path (here .) to a logical path (here Top), which will fix the discrepancy.
But Top is a poor name for a library, so you should replace it with something else. Moreover, that name will serve as the installation path for your library, so choose a meaningful name (e.g., RegexDerivatives), as that is the name users will be using.
For an application I am running, there is a run time error as it cannot find libwayland-client.so.0 shared object. How do I know which package provides it and where do I add it. I tried as shown below but it gave me a Nothing PROVIDES error.
CORE_IMAGE_EXTRA_INSTALL += "libwayland-client"
You don't typically work with single files when building Yocto images
In reverse order
You install packages to the image
You build packages by using a recipe
You find (or as a last resort write) recipes as part of layers.
Generally when something is missing you take the following steps:
Check the layerindex https://layers.openembedded.org/layerindex/branch/master/recipes/?q=wayland It tells you that there is a recipe called wayland in layer openembedded-core
Add the layer in question. openembedded-core is already contained in Yocto's poky (directly under the name meta, just to confuse the newcomer...), so nothing to add in this example
Create the environment listing of the recipe in question, bitbake -e wayland >wayland.env
Check what packages the recipe in question creates grep ^PACKAGES= wayland.env. In this case it is easy because there is really only one package wayland (-debug, -dev etc. are special purpose that would not contain the library)
Add a package to the image by its package name. How to do that exactly depends on the image type you create. The variable name given in the question works for some images, but not all. Search for IMAGE_INSTALL in the manual https://www.yoctoproject.org/docs/2.6.1/mega-manual/mega-manual.html for other options.
Once you have built the recipe in question you can also check what files are contained in a package (In this case recipe name and package name are identical, but that is not always the case. Some recipes build more than one package suitable for installation, so obviously they need to use different names)
$ oe-pkgdata-util list-pkg-files wayland
wayland:
/usr/lib/libwayland-client.so.0
/usr/lib/libwayland-client.so.0.3.0
/usr/lib/libwayland-cursor.so.0
/usr/lib/libwayland-cursor.so.0.0.0
/usr/lib/libwayland-server.so.0
/usr/lib/libwayland-server.so.0.1.0
I am running CoqIDE to use read the textbook series "Software Foundations", I am currently reading the volume "Logical Foundations". I just started Chapter 2 (Induction), but when I try to run the line
From LF Require Import Basics.
I get an error statement
The file ...\LF\Basics.vo contains library
Basics and not library LF.Basics
I tried renaming the directory the file was located in, and recompiled the buffers, but neither of these actions helped. What Shoudl i do in order to solve this problem?
We've been improving the explanation in the soon-to-be-released new version of LF. Here is the relevant bit:
For the [Require Export] to work, Coq needs to be able to
find a compiled version of [Basics.v], called [Basics.vo], in a directory
associated with the prefix [LF]. This file is analogous to the [.class]
files compiled from [.java] source files and the [.o] files compiled from
[.c] files.
First create a file named [_CoqProject] containing the following line
(if you obtained the whole volume "Logical Foundations" as a single
archive, a [_CoqProject] should already exist and you can skip this step):
[-Q . LF]
This maps the current directory ("[.]", which contains [Basics.v],
[Induction.v], etc.) to the prefix (or "logical directory") "[LF]".
PG and CoqIDE read [_CoqProject] automatically, so they know to where to
look for the file [Basics.vo] corresponding to the library [LF.Basics].
Once [_CoqProject] is thus created, there are various ways to build
[Basics.vo]:
- In Proof General: The compilation can be made to happen automatically
when you submit the [Require] line above to PG, by setting the emacs
variable [coq-compile-before-require] to [t].
- In CoqIDE: Open [Basics.v]; then, in the "Compile" menu, click
on "Compile Buffer".
- From the command line: Generate a [Makefile] using the [coq_makefile]
utility, that comes installed with Coq (if you obtained the whole
volume as a single archive, a [Makefile] should already exist
and you can skip this step):
[coq_makefile -f _CoqProject *.v -o Makefile]
Note: You should rerun that command whenever you add or remove Coq files
to the directory.
Then you can compile [Basics.v] by running [make] with the corresponding
[.vo] file as a target:
[make Basics.vo]
All files in the directory can be compiled by giving no arguments:
[make]
Under the hood, [make] uses the Coq compiler, [coqc]. You can also
run [coqc] directly:
[coqc -Q . LF Basics.v]
But [make] also calculates dependencies between source files to compile
them in the right order, so [make] should generally be prefered over
explicit [coqc].
If you have trouble (e.g., if you get complaints about missing
identifiers later in the file), it may be because the "load path"
for Coq is not set up correctly. The [Print LoadPath.] command
may be helpful in sorting out such issues.
In particular, if you see a message like
[Compiled library Foo makes inconsistent assumptions over
library Bar]
check whether you have multiple installations of Coq on your machine.
It may be that commands (like [coqc]) that you execute in a terminal
window are getting a different version of Coq than commands executed by
Proof General or CoqIDE.
- Another common reason is that the library [Bar] was modified and
recompiled without also recompiling [Foo] which depends on it. Recompile
[Foo], or everything if too many files are affected. (Using the third
solution above: [make clean; make].)
One more tip for CoqIDE users: If you see messages like [Error:
Unable to locate library Basics], a likely reason is
inconsistencies between compiling things _within CoqIDE_ vs _using
[coqc] from the command line_. This typically happens when there
are two incompatible versions of [coqc] installed on your
system (one associated with CoqIDE, and one associated with [coqc]
from the terminal). The workaround for this situation is
compiling using CoqIDE only (i.e. choosing "make" from the menu),
and avoiding using [coqc] directly at all. *)
SQLAPI++ has an unusual feature where you set a string to tell it where to find the ODBC shared library. In my case this is libtdsodbc.so, and my application actually links that library at build time, but at runtime this is not enough for SQLAPI++ to work.
My code is:
SAConnection conn;
conn.setOption("ODBC.LIBS") = "libtdsodbc.so";
conn.Connect("SERVER=...", "", "", SA_ODBC_Client);
ODBC.LIBS is documented like this:
Forces SQLAPI++ Library to use specified ODBC manager library.
The above code works if you set LD_LIBRARY_PATH to a directory containing libtdsodbc.so. But if you don't, Connect() fails:
libtdsodbc.so: cannot open shared object file: No such file or directory
DBMS API Library 'libtdsodbc.so' loading fails
This library is a part of DBMS client installation, not SQLAPI++
Make sure DBMS client is installed and
this required library is available for dynamic loading
Linux/Unix:
1) The directories in the user's LD_LIBRARY_PATH environment variable
2) The list of libraries cached in /etc/ld.so.cache
3) /usr/lib, followed by /lib
It works again if you set ODBC.LIBS to a full path rather than just a filename. But how can the application know which path?
My application (outside of SQLAPI++) finds libtdsodbc.so via its RUNPATH which is set at build time. This path is not a system path like /usr/lib. I'd like to have SQLAPI++ use the same library which is loaded in the application at runtime.
One idea is for the application to inspect its own RUNPATH, search for libtdsobc.so, and use that path. But this requires quite a bit of fiddly code to basically reimplement what ld.so already does.
I don't want to bake the path into the executable at build time separately from RUNPATH, because I sometimes edit RUNPATH before deployment (and then I'd need to edit two things).
Ideally I would like to tell SQLAPI++ to just use the library which is already loaded. I can figure this path out by running lsof -p PID | grep libtdsodbc.so but running shell commands from within the executable is not a good solution (and again I would rather not reimplement lsof).
You could either use dl_iterate_phdr (the link also includes a sample code which prints out lib names) or manually parse /proc/self/maps.
I am using Eclipse Juno CDT for a class I am taking, but it is telling me it can't resolve types found in include files, and these aren't headers I wrote.
The program I wrote compiles and runs exactly as it should if I run it through g++ via the command line. The problem is that I can't debug in Eclipse because it doesn't recognize even basic types like string. Also, no code completion. It finds the include files just fine, I can open those and look at the contents, but it still won't resolve types.
I've seen lots of suggestions for people with similar problems, but those all turned out to be not finding the include files, which isn't my problem. Any suggestions?
Maybe the types are in a namespace and you're not qualifying them (and not using a using declaration).
You likely have included the proper directory for the headers themselves. On my system it is: /usr/include/c++/4.4.6/
However, you probably don't have the directory containing the definition of the macro _GLIBCXX_BEGIN_NAMESPACE. Without this macro definition eclipse does not know that the stl types are in the std namespace. On my system this macro definition is squirreled away beneath the main c++ dir. Try adding the following paths to your include list:
/usr/include/c++/4.4.6/x86_64-redhat-linux
/usr/include/c++/4.4.6/x86_64-redhat-linux/bits
If you're not on redhat look for something similar. You can go to /usr/include and run the following grep to look for the headers with the necessary macro definition:
grep -R -P "define\\s*_GLIBCXX_BEGIN_NAMESPACE\(" .