Failure expanding variable PN

[Francis Giraldeau]

Hello, with Yocto 2.1, it seems that the signature of function getVar() changed, hence breaking the tutorial ch04.

$ bitbake -s
ERROR: ExpansionError during parsing /data/francis/bitbakeguide/ch04/build/../meta-tutorial/recipes-tutorial/first/first_0.1.bb: Failure expanding variable PN, expression was ${@bb.parse.BBHandler.vars_from_file(d.getVar('FILE'),d)[0] or 'defaultpkgname'} which triggered exception TypeError: getVar() takes at least 3 arguments (2 given)

I added "False" as a second argument, which is for "expand", and it works correctly.

diff --git a/ch04/meta-tutorial/conf/bitbake.conf b/ch04/meta-tutorial/conf/bitbake.conf
index c2ed926..e65de03 100644
--- a/ch04/meta-tutorial/conf/bitbake.conf
+++ b/ch04/meta-tutorial/conf/bitbake.conf
@@ -40,10 +40,10 @@ OVERRIDES = "local:${MACHINE}:${TARGET_OS}:${TARGET_ARCH}"
 P = "${PN}-${PV}"
 PERSISTENT_DIR = "${TMPDIR}/cache"
 PF = "${PN}-${PV}-${PR}"
-PN = "${@bb.parse.BBHandler.vars_from_file(d.getVar('FILE'),d)[0] or 'defaultpkgname'}"
-PR = "${@bb.parse.BBHandler.vars_from_file(d.getVar('FILE'),d)[2] or 'r0'}"
+PN = "${@bb.parse.BBHandler.vars_from_file(d.getVar('FILE', False),d)[0] or 'defaultpkgname'}"
+PR = "${@bb.parse.BBHandler.vars_from_file(d.getVar('FILE', False),d)[2] or 'r0'}"
 PROVIDES = ""
-PV = "${@bb.parse.BBHandler.vars_from_file(d.getVar('FILE'),d)[1] or '1.0'}"
+PV = "${@bb.parse.BBHandler.vars_from_file(d.getVar('FILE', False),d)[1] or '1.0'}"
 RESUMECOMMAND = ""
 RESUMECOMMAND_wget = "/usr/bin/env wget -c -t 5 --passive-ftp -P ${DL_DIR} ${URI}"
 S = "${WORKDIR}/${P}"

[Harald Achitz]

Hi Francis,
thanks a lot for your report!
This is interesting. The 2.1 bitbake documentation does not mention a change in the data store API, getVar still takes 2 arguments, where the second one is defaulted to False, see bitbake 2.1 docu datastore
So I am unsure why this is required, I will have to investigate this later today or tomorrow,
I have to admit that until now I did not update and test the tutorial to version 2.1, but I guess I will have to do this now, so it might become weekend until I am done.

[Francis Giraldeau]

It turns out that base.bbclass is also affected by this change

diff --git a/ch04/meta-tutorial/classes/base.bbclass b/ch04/meta-tutorial/classes/base.bbclass
index 0972d69..71d9ec1 100644
--- a/ch04/meta-tutorial/classes/base.bbclass
+++ b/ch04/meta-tutorial/classes/base.bbclass
@@ -43,7 +43,7 @@ python do_showdata() {
        bb.data.emit_env(sys.__stdout__, d, True)
        # emit the metadata which isnt valid shell
        for e in bb.data.keys(d):
-               if d.getVarFlag(e, 'python'):
+               if d.getVarFlag(e, 'python', False):
                        bb.plain("\npython %s () {\n%s}" % (e, d.getVar(e, True)))
 }

@@ -52,7 +52,7 @@ do_listtasks[nostamp] = "1"
 python do_listtasks() {
        import sys
        for e in bb.data.keys(d):
-               if d.getVarFlag(e, 'task'):
+               if d.getVarFlag(e, 'task', False):
                        bb.plain("%s" % e)
 }

[Harald Achitz]

Hi Francis,
are you using possible python3, its maybe default on the latest Ubuntu.
python3 is not supported by Yocto, see the Yocto documentation required-git-tar-and-python-versions.
I am just asking because the d.getVarFlag, like the d.getVar mentioned earlier, does also default the expand flag, so it seems a bit strange that you have to provide it explicit.

[Francis Giraldeau]

Sorry, I did not refreshed the page before posting the second comment ;-)

I saw that the bitbake documentation was updated:

69b69193 bitbake/doc/bitbake-user-manual/bitbake-user-manual-execution.xml (Richard Purdie   2015-06-18 15:14:19 +0100 309)      PN = "${@bb.parse.BBHandler.vars_from_file(d.getVar('FILE', False),d)[0] or 'defaultpkgname'}"

Ref: http://git.yoctoproject.org/cgit/cgit.cgi/poky/tree/bitbake/doc/bitbake-user-manual/bitbake-user-manual-metadata.xml#n330

Could it be possible the python code does not define the default value for the expand argument?

bitbake/lib/bb/data_smart.py:

    def getVar(self, var, expand, noweakdefault=False, parsing=False):
        return self.getVarFlag(var, "_content", expand, noweakdefault, parsing)

Thanks!

[Francis Giraldeau]

I do have both Python 2 and 3 on my system, but the default one is Python 2.

$ python --version
Python 2.7.10

[Harald Achitz]

Ok, thanks for the info Francis!
I will have to check this later on my build box with the latest yocto and bitbake version.

[Harald Achitz]

Hi Francis

I have a problem to reproduce this using the latest yocto download YP Core - Krogoth 2.1

setup the environment as written in chapter 3 ,

  export bitbake_root_dir=~/tmp/yocto/poky-krogoth-15.0.0/bitbake
  export PATH=$bitbake_root_dir/bin:$PATH
  export PYTHONPATH=$bitbake_root_dir/lib:$PYHTONPATH

bitbake is this,

[a4z@x230 build]$ which bitbake
~/tmp/yocto/poky-krogoth-15.0.0/bitbake/bin/bitbake

I am cloning the bbTutor repository, change into the ch04 directory,
create the build/conf/bblayers.conf as written in the tutorial

[a4z@x230 build]$ pwd
/home/a4z/tmp/yocto/bbTutor/ch04/build
[a4z@x230 build]$ tree ../
../
├── build
│   └── conf
│       └── bblayers.conf
└── meta-tutorial
    ├── classes
    │   └── base.bbclass
    └── conf
        ├── bitbake.conf
        └── layer.conf

5 directories, 4 files
[a4z@x230 build]$ bitbake --version
BitBake Build Tool Core version 1.30.0
[a4z@x230 build]$ bitbake -vvvD
Nothing to do.  Use 'bitbake world' to build everything, or run 'bitbake --help' for usage information.
DEBUG: Removed the following variables from the environment: HISTTIMEFORMAT, LC_NUMERIC, HISTFILE, IMSETTINGS_MODULE, GNOME_DESKTOP_SESSION_ID, LC_MEASUREMENT, LESSOPEN, LC_PAPER, QT_IM_MODULE, XDG_SEAT, XDG_VTNR, WINDOWPATH, LANG, XAUTHORITY, SESSION_MANAGER, LC_MONETARY, HISTSIZE, RBENV_SHELL, WINDOWID, IMSETTINGS_INTEGRATE_DESKTOP, GPG_AGENT_INFO, HISTFILESIZE, PYTHONUSERBASE, USERNAME, XDG_SESSION_DESKTOP, XDG_RUNTIME_DIR, PYTHONPATH, SSH_AUTH_SOCK, VTE_VERSION, GDMSESSION, XMODIFIERS, XDG_MENU_PREFIX, XDG_CURRENT_DESKTOP, XDG_SESSION_ID, DBUS_SESSION_BUS_ADDRESS, _, DESKTOP_SESSION, DISPLAY, OLDPWD, HOSTNAME, GDM_LANG, HISTCONTROL, SHLVL, MAIL, LC_TIME, LS_COLORS
DEBUG: Inheriting /home/a4z/tmp/yocto/bbTutor/ch04/meta-tutorial/classes/base.bbclass (from configuration INHERITs:0)
DEBUG: Clearing SRCREV cache due to cache policy of: clear
DEBUG: Using cache in '/home/a4z/tmp/yocto/bbTutor/ch04/build/tmp/cache/local_file_checksum_cache.dat'
DEBUG: Using cache in '/home/a4z/tmp/yocto/bbTutor/ch04/build/tmp/cache/bb_codeparser.dat'
DEBUG: Features set [3] (was [3])
DEBUG: Base environment change, triggering reparse
DEBUG: Inheriting /home/a4z/tmp/yocto/bbTutor/ch04/meta-tutorial/classes/base.bbclass (from configuration INHERITs:0)
DEBUG: Clearing SRCREV cache due to cache policy of: clear
DEBUG: Using cache in '/home/a4z/tmp/yocto/bbTutor/ch04/build/tmp/cache/local_file_checksum_cache.dat'
DEBUG: Using cache in '/home/a4z/tmp/yocto/bbTutor/ch04/build/tmp/cache/bb_codeparser.dat'
[a4z@x230 build]$ bitbake -s
ERROR: no recipe files to build, check your BBPATH and BBFILES?

Summary: There was 1 ERROR message shown, returning a non-zero exit code.

even the output of bitbake -s is OK, even if that's at this point not part of the tutorial, but this error is expected.

I am running the stuff on a RHEL 7 with Python 2.7.5

is it possible that your PYTHONPATH was set incorrect, can you give me some more info that helps me to reproduce the problem?

[Harald Achitz]

Issue #3 was marked as a duplicate of this issue.

[Harald Achitz]

fixed in in the last commit

also removed cache files in earlier commits that seemed to be by mistake in the git repo which made this problem not appear in my local chapter 4 example.

Thanks Francis Giraldeau and some Anonymous person (#3) for reporting the problem.

[Harald Achitz]

I hope all occurrences are updated in the samples, if you find further problems with this issue, please reopen or file a new one. Thanks!