$ gdb usr/bin/initdb
...
(gdb) set args -D pgd
(gdb) b bootstrap_template1
Breakpoint 1 at 0x804aef0: file initdb.c, line 1341.
(gdb) run
Starting program: /home/knt/farm/fake-root/usr/bin/initdb -D pgd
The files belonging to this database system will be owned by user "knt".
This user must also own the server process.

The database cluster will be initialized with locale tr_TR.
The default database encoding has accordingly been set to LATIN5.

creating directory pgd ... ok
creating directory pgd/global ... ok
creating directory pgd/pg_xlog ... ok
creating directory pgd/pg_xlog/archive_status ... ok
creating directory pgd/pg_clog ... ok
creating directory pgd/pg_subtrans ... ok
creating directory pgd/pg_twophase ... ok
creating directory pgd/pg_multixact/members ... ok
creating directory pgd/pg_multixact/offsets ... ok
creating directory pgd/base ... ok
creating directory pgd/base/1 ... ok
creating directory pgd/pg_tblspc ... ok
selecting default max_connections ... 10
selecting default shared_buffers/max_fsm_pages ... 50/20000
creating configuration files ... ok

Breakpoint 1, bootstrap_template1 (short_version=0x8056868 "8.2") at initdb.c:1341
1341            char       *talkargs = "";
(gdb) n
1345            printf(_("creating template1 database in %s/base/1 ... "), pg_data);
(gdb)
1346            fflush(stdout);
(gdb) 
creating template1 database in pgd/base/1 ... 1348              if (debug)
(gdb) 
1351            bki_lines = readfile(bki_file);
(gdb) 
1355            snprintf(headerline, sizeof(headerline), "# PostgreSQL %s\n",
(gdb) 
1358            if (strcmp(headerline, *bki_lines) != 0)
(gdb) 
1368            bki_lines = replace_token(bki_lines, "POSTGRES", effective_user);
(gdb) 
1370            bki_lines = replace_token(bki_lines, "ENCODING", encodingid);
(gdb) 
1378            snprintf(cmd, sizeof(cmd), "LC_COLLATE=%s", lc_collate);
(gdb) 
1379            putenv(xstrdup(cmd));
(gdb) 
1381            snprintf(cmd, sizeof(cmd), "LC_CTYPE=%s", lc_ctype);
(gdb) 
1382            putenv(xstrdup(cmd));
(gdb) 
1384            unsetenv("LC_ALL");
(gdb) 
1387            unsetenv("PGCLIENTENCODING");
(gdb) 
1389            snprintf(cmd, sizeof(cmd),
(gdb) 
1393            PG_CMD_OPEN;
(gdb) 
1395            for (line = bki_lines; *line != NULL; line++)
(gdb) FATAL:  failed to initialize TimeZone to "UNKNOWN"

1397                    PG_CMD_PUTS(*line);
(gdb) 

Program received signal SIGPIPE, Broken pipe.
0xb7d3e95e in write () from /lib/tls/libc.so.6
(gdb)