Thank you. Pulled with git, and that went well, with these steps:
git clone
https://gitlab.com/freepascal.org/lazarus/lazarus.git lazarus-main
cd lazarus-main
Then,
make clean
make bigide
make bigide failed, and though it is easy to see where, it is not especially helpful at this point:
Free Pascal Compiler version 3.0.4+dfsg-23 [2019/11/25] for x86_64
Copyright (c) 1993-2017 by Florian Klaempfl and others
(1002) Target OS: Linux for x86-64
(3104) Compiling lazutils.pas
(3104) Compiling avglvltree.pas
(3104) Compiling laz_avl_tree.pp
/home/wmeyer/lazarus-main/components/lazutils/laz_avl_tree.pp(95,33) Hint: (5024) Parameter "aNode" not used
/home/wmeyer/lazarus-main/components/lazutils/laz_avl_tree.pp(98,30) Hint: (5024) Parameter "aNode" not used
(3104) Compiling lazfileutils.pas
(3104) Compiling lazutf8.pas
(3104) Compiling fpcadds.pas
/home/wmeyer/lazarus-main/components/lazutils/lazutf8.pas(1213,12) Error: (3026) Wrong number of parameters specified for call to "Pos"
The difficulty being that as this is a first attempt at building the IDE, it seems more than a little foolish for me to start editing source code.