broken sam semantic track

partial_volvox.conf

[main:database]
db_adaptor    = Bio::DB::SeqFeature::Store
db_args       = -adaptor memory
                -dir '/Library/WebServer/Documents/gbrowse2/databases/volvox'


[samdb:database]
db_adaptor     = Bio::DB::Sam
db_args        = -fasta /Library/WebServer/Documents/gbrowse2/databases/volvox/volvox.fa
                 -bam  /Library/WebServer/Documents/gbrowse2/databases/volvox/volvox.sort.bam
search options = none

[TRACK DEFAULTS]
glyph         = generic
height        = 10
bgcolor       = lightgrey
fgcolor       = black
font2color    = blue
label density = 25
bump density  = 100
database      = main
# where to link to when user clicks in detailed view
link          = AUTO

[Alignments]
feature      = match
glyph        = segments
key          = Example alignments

[Alignments:10000]
glyph        = box
label        = 0

[Alignments:45000]
glyph        = box
bump         = 0
label        = 0

[Reads]
feature        = match
glyph          = segments
draw_target    = 1
show_mismatch  = 1
mismatch_color = red
database       = samdb
bgcolor        = blue
height         = 5
label density  = 50
bump           = fast
key            = Reads
category       = Reads

[Reads:5000]
feature        = coverage
glyph          = wiggle_density
database       = samdb
height         = 20
bicolor_pivot  = 90
pos_color      = blue
neg_color      = red
label          = 0
draw_target    = 0
show_mismatch  = 0
bump           = 0

[CoverageDensity]
feature        = coverage
glyph          = wiggle_density
database       = samdb
height         = 20
bicolor_pivot  = 90
pos_color      = blue
neg_color      = red
key            = Coverage (density)
category       = Reads
label          = 0

[Pairs]
feature        = read_pair
glyph          = segments
draw_target    = 1
show_mismatch  = 1
mismatch_color = red
database       = samdb
bgcolor        = violet
height         = 5
label density  = 50
bump           = fast
key            = Read pairs
category       = Reads

[Pairs:2000]
feature        = coverage
glyph          = wiggle_density
database       = samdb
height         = 20
bicolor_pivot  = 90
pos_color      = purple
neg_color      = red
label          = 0
draw_target    = 0
show_mismatch  = 0
bump           = 0