所以我在 ubuntu 18.10 上安装了qtcreator包。
我发现要获取示例，我还需要qtbase5-examples和qtbase5-doc-html包。
但是在 qtcreator 的欢迎屏幕的下拉菜单中仍然没有显示示例。
我发现有类似问题的人（例如archlinux），但尝试修复路径问题不允许示例出现在qtcreator中。
艾诺？
所以看起来nautilus/Files和其他软件在ubuntu中使用SI单位来显示文件大小已经有一段时间了。
但这与ls、du和df等仍然使用 IEC 二进制单位的cli命令相当不一致。
通常可以使用环境变量 BLOCK_SIZE 来更改 cli 命令的行为，但这不起作用（编辑：17.10 此处）（https://www.gnu.org/software/coreutils/manual/html_node/Block-size .html#块大小）
BLOCK_SIZE=si ls -l -h
仍以 IEC 二进制单位显示
export BLOCK_SIZE=si
ls -l -h
行为相同或使用 BLOCKSIZE
这是一个错误吗？它是否已被 ubuntu 修补/删除？
编辑：我想使用 env var 在我的全局定义它.bashrc
当我输入：
$ mount|grep snap
/var/lib/snapd/snaps/ubuntu-core_352.snap on /snap/ubuntu-core/352 type squashfs (ro,relatime)
/var/lib/snapd/snaps/ubuntu-core_423.snap on /snap/ubuntu-core/423 type squashfs (ro,relatime)
/var/lib/snapd/snaps/ubuntu-core_122.snap on /snap/ubuntu-core/122 type squashfs (ro,relatime)
我看到几个旧的快照“已安装”并且可用，而只有最新版本用作当前版本/snap/ubuntu-core
这没什么大不了的，但我需要旧的 ubuntu 内核吗？这不是没有删除的错误吗？我可以简单地卸载并删除文件吗？
安装16.04时，如果我想安装3rd 方模块/驱动程序，我被要求关闭“安全启动” 。
我没有遵守。
当我手动安装我使用的唯一 3rd 方驱动程序 ( bcmwl-kernel-source ) 时，我再次被要求（在安装包期间）关闭“安全启动”。
在15.10中使用bcmwl-kernel-source与Secure Boot非常好。这似乎与我的错误无关。
因此，这看起来确实像 Ubuntu 拒绝签署 3rd 方驱动程序/模块以使其工作（？？）与“安全启动”。或者似乎认为 3rd 方模块不安全并破坏“安全启动”，因此强制禁用它以使其清楚？我对吗 ？
我刚买了一个SSD来替换笔记本电脑中的HDD（Dell Inspiron 15 3521）。所以我迁移了Windows分区， Ubuntu的根分区，并制作了一个保留在硬盘上的bcache缓存分区。HDD现在位于 DVD 驱动器位置内的 HDD 盒中。/home
所以问题是我的硬盘驱动器 （？）有时会开始发出滴答声（但不是咔哒声），就像手表一样，但声音有点大，每秒或半秒，重复和连续。
这不仅很烦人，而且我担心HDD的健康。
特别奇怪的是，我的新设置对HDD的访问是有限的。HDD 上还有/var分区和交换区，但我有 8G RAM。和支持bcache /home分区。
我想可能是硬盘的磁头反复停车。但是在网上找到的一个简单脚本显示输出的Load_Cycle_Count值没有变化smartctl -a /dev/sdb
不断增加的令人担忧的值是Raw_Read_Error_Rate但据说对希捷硬盘毫无意义（此处为ST500LT012）
即使当我切换到控制台并停止lightdm时，该声音仍在继续。
但是，如果我使用gsmartcontrol运行一个简短的自检，那声音会突然停止。简短的自检顺利通过。我在备份bcache分区上运行badblocks，没有发现错误。/home
我不知道是什么原因引起的声音。它似乎不是一个锤击硬盘的过程。我只运行铬和一个终端
smartctl -a 的输出：
$ smartctl -a /dev/sdb
smartctl 6.2 2013-07-26 r3841 [x86_64-linux-3.16.0-31-generic] (local build)
Copyright (C) 2002-13, Bruce Allen, Christian Franke, www.smartmontools.org
=== START OF INFORMATION SECTION ===
Device Model: ST500LT012-1DG142
Serial Number: XXXXXXXX
LU WWN Device Id: 5 000c50 xxxxxxxxxx
Firmware Version: 0001SDM1
User Capacity: 500 107 862 016 bytes [500 GB]
Sector Sizes: 512 bytes logical, 4096 bytes physical
Rotation Rate: 5400 rpm
Device is: Not in smartctl database [for details use: -P showall]
ATA Version is: ATA8-ACS T13/1699-D revision 4
SATA Version is: SATA 3.0, 6.0 Gb/s (current: 3.0 Gb/s)
Local Time is: Sat Mar 21 01:12:10 2015 CET
SMART support is: Available - device has SMART capability.
SMART support is: Enabled
=== START OF READ SMART DATA SECTION ===
SMART overall-health self-assessment test result: PASSED
General SMART Values:
Offline data collection status: (0x82) Offline data collection activity
was completed without error.
Auto Offline Data Collection: Enabled.
Self-test execution status: ( 0) The previous self-test routine completed
without error or no self-test has ever
been run.
Total time to complete Offline
data collection: ( 0) seconds.
Offline data collection
capabilities: (0x7b) SMART execute Offline immediate.
Auto Offline data collection on/off support.
Suspend Offline collection upon new
command.
Offline surface scan supported.
Self-test supported.
Conveyance Self-test supported.
Selective Self-test supported.
SMART capabilities: (0x0003) Saves SMART data before entering
power-saving mode.
Supports SMART auto save timer.
Error logging capability: (0x01) Error logging supported.
General Purpose Logging supported.
Short self-test routine
recommended polling time: ( 1) minutes.
Extended self-test routine
recommended polling time: ( 103) minutes.
Conveyance self-test routine
recommended polling time: ( 2) minutes.
SCT capabilities: (0x1035) SCT Status supported.
SCT Feature Control supported.
SCT Data Table supported.
SMART Attributes Data Structure revision number: 10
Vendor Specific SMART Attributes with Thresholds:
ID# ATTRIBUTE_NAME FLAG VALUE WORST THRESH TYPE UPDATED WHEN_FAILED RAW_VALUE
1 Raw_Read_Error_Rate 0x000f 119 099 006 Pre-fail Always - 226511072
3 Spin_Up_Time 0x0003 100 099 000 Pre-fail Always - 0
4 Start_Stop_Count 0x0032 099 099 020 Old_age Always - 1883
5 Reallocated_Sector_Ct 0x0033 100 100 036 Pre-fail Always - 0
7 Seek_Error_Rate 0x000f 076 060 030 Pre-fail Always - 47056689
9 Power_On_Hours 0x0032 098 098 000 Old_age Always - 2357 (113 43 0)
10 Spin_Retry_Count 0x0013 100 100 097 Pre-fail Always - 0
12 Power_Cycle_Count 0x0032 099 099 020 Old_age Always - 1582
184 End-to-End_Error 0x0032 100 100 099 Old_age Always - 0
187 Reported_Uncorrect 0x0032 100 100 000 Old_age Always - 0
188 Command_Timeout 0x0032 100 100 000 Old_age Always - 0
189 High_Fly_Writes 0x003a 100 100 000 Old_age Always - 0
190 Airflow_Temperature_Cel 0x0022 079 048 045 Old_age Always - 21 (Min/Max 19/21)
191 G-Sense_Error_Rate 0x0032 100 100 000 Old_age Always - 100
192 Power-Off_Retract_Count 0x0032 100 100 000 Old_age Always - 46
193 Load_Cycle_Count 0x0032 099 099 000 Old_age Always - 3935
194 Temperature_Celsius 0x0022 021 052 000 Old_age Always - 21 (0 11 0 0 0)
197 Current_Pending_Sector 0x0012 100 100 000 Old_age Always - 0
198 Offline_Uncorrectable 0x0010 100 100 000 Old_age Offline - 0
199 UDMA_CRC_Error_Count 0x003e 200 200 000 Old_age Always - 0
240 Head_Flying_Hours 0x0000 098 098 000 Old_age Offline - 156817845913887
241 Total_LBAs_Written 0x0000 100 253 000 Old_age Offline - 6713158176
242 Total_LBAs_Read 0x0000 100 253 000 Old_age Offline - 8448037256
254 Free_Fall_Sensor 0x0032 100 100 000 Old_age Always - 0
SMART Error Log Version: 1
No Errors Logged
SMART Self-test log structure revision number 1
Num Test_Description Status Remaining LifeTime(hours) LBA_of_first_error
# 1 Short offline Completed without error 00% 2354 -
# 2 Short offline Completed without error 00% 2342 -
# 3 Short offline Completed without error 00% 2339 -
# 4 Short offline Completed without error 00% 2334 -
# 5 Short offline Completed without error 00% 2333 -
# 6 Short offline Completed without error 00% 2307 -
# 7 Short offline Completed without error 00% 2306 -
# 8 Short offline Completed without error 00% 2295 -
# 9 Short offline Completed without error 00% 2295 -
#10 Short offline Completed without error 00% 2291 -
#11 Short offline Completed without error 00% 2283 -
#12 Short offline Completed without error 00% 1198 -
#13 Extended offline Completed without error 00% 937 -
#14 Short offline Completed without error 00% 935 -
#15 Short offline Completed without error 00% 356 -
#16 Extended offline Completed without error 00% 122 -
#17 Short offline Completed without error 00% 120 -
#18 Short offline Completed without error 00% 14 -
#19 Short offline Completed without error 00% 0 -
SMART Selective self-test log data structure revision number 1
SPAN MIN_LBA MAX_LBA CURRENT_TEST_STATUS
1 0 0 Not_testing
2 0 0 Not_testing
3 0 0 Not_testing
4 0 0 Not_testing
5 0 0 Not_testing
Selective self-test flags (0x0):
After scanning selected spans, do NOT read-scan remainder of disk.
If Selective self-test is pending on power-up, resume after 0 minute delay.