This is the error reported by jhbuild trying to "swith" from master to gnome-2-28

*** Checkout evolution-data-server *** [1/3]
git stash save jhbuild-stash
Saved working directory and index state "On master: jhbuild-stash"
HEAD is now at 5e2dbe7 Post release version bump
git show-ref --quiet --verify refs/heads/gnome-2-28
git checkout --track -b gnome-2-28 origin/gnome-2-28
fatal: git checkout: updating paths is incompatible with switching branches/forcing
Did you intend to checkout 'origin/gnome-2-28' which can not be resolved as commit?
*** Error during phase checkout of evolution-data-server: ########## Errore nell'eseguire git checkout --track -b gnome-2-28 origin/gnome-2-28 *** [1/3]


I tryed to run git status, it seems there are untracked files..

betatester@luca-desktop:~/checkout/gnome2/evolution-data-server$ git status
# On branch master
# Untracked files:
#   (use "git add <file>..." to include in what will be committed)
#
#	INSTALL
#	addressbook/backends/groupwise/create-account
#	addressbook/libebook/Evolution-DataServer-Addressbook-common.c
#	addressbook/libebook/Evolution-DataServer-Addressbook-skels.c
#	addressbook/libebook/Evolution-DataServer-Addressbook-stubs.c
#	addressbook/libebook/Evolution-DataServer-Addressbook.h
#	addressbook/libedata-book/Evolution-DataServer-Addressbook-common.c
#	addressbook/libedata-book/Evolution-DataServer-Addressbook-skels.c
#	addressbook/libedata-book/Evolution-DataServer-Addressbook-stubs.c
#	addressbook/libedata-book/Evolution-DataServer-Addressbook.h
#	addressbook/tests/ebook/test-categories
#	addressbook/tests/ebook/test-changes
#	addressbook/tests/ebook/test-date
#	addressbook/tests/ebook/test-ebook
#	addressbook/tests/ebook/test-ebook-async
#	addressbook/tests/ebook/test-ebook-view
#	addressbook/tests/ebook/test-nonexistent-id
#	addressbook/tests/ebook/test-photo
#	addressbook/tests/ebook/test-query
#	addressbook/tests/ebook/test-search
#	addressbook/tests/ebook/test-self
#	addressbook/tests/ebook/test-stress-bookviews
#	addressbook/tests/ebook/test-string
#	addressbook/tests/ebook/test-undefinedfield
#	addressbook/tests/ebook/test-untyped-phones
#	addressbook/tests/vcard/dump-vcard
#	calendar/backends/weather/Locations.xml
#	calendar/libecal/Evolution-DataServer-Calendar-common.c
#	calendar/libecal/Evolution-DataServer-Calendar-skels.c
#	calendar/libecal/Evolution-DataServer-Calendar-stubs.c
#	calendar/libecal/Evolution-DataServer-Calendar.h
#	calendar/libecal/e-cal-marshal.c
#	calendar/libecal/e-cal-marshal.h
#	calendar/libedata-cal/Evolution-DataServer-Calendar-common.c
#	calendar/libedata-cal/Evolution-DataServer-Calendar-skels.c
#	calendar/libedata-cal/Evolution-DataServer-Calendar-stubs.c
#	calendar/libedata-cal/Evolution-DataServer-Calendar.h
#	calendar/tests/ecal/test-ecal
#	calendar/tests/ecal/test-recur
#	calendar/tests/ecal/test-search
#	camel/camel-index-control-1.2
#	camel/camel-lock-helper-1.2
#	camel/camel-mime-tables.c
#	doltcompile
#	doltlibtool
#	evolution-data-server-zip
#	iconv-detect.h
#	libdb/dist/db.h
#	libdb/dist/db_archive
#	libdb/dist/db_checkpoint
#	libdb/dist/db_config.h
#	libdb/dist/db_cxx.h
#	libdb/dist/db_deadlock
#	libdb/dist/db_dump
#	libdb/dist/db_int.h
#	libdb/dist/db_int_def.h
#	libdb/dist/db_load
#	libdb/dist/db_printlog
#	libdb/dist/db_recover
#	libdb/dist/db_stat
#	libdb/dist/db_upgrade
#	libdb/dist/db_verify
#	libdb/dist/include.tcl
#	libedataserver/eds-version.h
#	libedataserver/test-source-list
#	libedataserverui/e-data-server-ui-marshal.c
#	libedataserverui/e-data-server-ui-marshal.h
#	libedataserverui/test-category-completion
#	libedataserverui/test-contact-store
#	libedataserverui/test-name-selector
#	libedataserverui/test-source-combo-box
#	libedataserverui/test-source-selector
#	servers/groupwise/build-timestamp.h
#	servers/groupwise/create-account
#	servers/groupwise/soap-test
#	src/Evolution-DataServer-common.c
#	src/Evolution-DataServer-skels.c
#	src/Evolution-DataServer-stubs.c
#	src/Evolution-DataServer.h
#	src/evolution-data-server
nothing added to commit but untracked files present (use "git add" to track)